What we know about U.S. investigations into Russia and possible ties to Trump's campaign

House Permanent Select Committee on Intelligence Chairman Devin Nunes (R-Calif) speaks to the media Mar. 7 about President Donald Trump's allegation that his campaign was the target of wiretaps on Capitol Hill in Washington. Photo by Aaron P. Bernstein/Reuters.

Questions about President Donald Trump's ties to Russia and links between his associates and the Kremlin have persisted since the early days of the 2016 election. Here's a comprehensive timeline of everything we know about the U.S. investigations of Trump's possible connections to Russia and Moscow's efforts to undermine democracy in America.

2016:

Spring

The government began its investigation into Russia's role in the U.S. presidential election last spring. It's unclear exactly when the probe was launched that year, but six agencies were involved from the start: the FBI, CIA, Justice Department, National Security Agency, the Office of the Director of National Intelligence and the Treasury Department. According to a BBC report, the investigation began after the CIA obtained a recording showing the Russian government planned to disrupt the election.

July

Christopher Steele, a former British intelligence agent, gave the FBI information alleging the Russian government was in contact with Trump's campaign. Steele's report also alleged that the Trump campaign had cooperated with Russia as the country hacked the emails of the Democratic National Committee and top Clinton campaign aides. Steele claimed he got the information while compiling opposition research on Trump for Republican and Democratic clients.

Steele also gave the FBI more information on Trump's ties with Russia in September. The information indicated that Trump's campaign knew as early as June that Russia was orchestrating a hacking operation to influence the election. Last month, Buzzfeed published Steele's findings, with a disclaimer that the information was unverified. The dossier claimed that Russia possessed compromising information about Trump's business ties in the country and his activities on a trip to Moscow.

Steele's report also claimed that the "Russian regime has been cultivating, supporting and assisting TRUMP for at least five years" in an effort to sow "divisions in western alliance." The summary noted that Russia had "compromised" Trump "sufficiently to be able to blackmail him." U.S. and foreign intelligence agencies are reportedly working to verify the claims in Steele's dossier, but so far the most damning charges remain unverified.

Donald Trump with his campaign manager Paul Manafort and daughter Ivanka during a walk through at the Republican National Convention in Cleveland last July. REUTERS/Rick Wilking/File Photo

October

In an extraordinary joint statement on Oct. 7, the Department of Homeland Security and Office of the Director of National Intelligence said the U.S. intelligence community believed Russia was behind a hacking operation "to interfere with the U.S. election process." The agencies added: "We believe, based on the scope and sensitivity of these efforts, that only Russia's senior-most officials could have authorized these activities."

On Oct. 15, the FBI got a warrant from the Foreign Intelligence Surveillance Court to obtain records relating to Russia's effort to influence the election, according to the BBC. Two weeks later, on Nov. 1, NBC reported that the FBI had started a "preliminary inquiry" into the foreign business dealings of Paul Manafort, who had served briefly as Trump's campaign manager before stepping down. Manafort resigned in August over news reports of his business connections in Russia, and his work as a consultant for a pro-Russian political party in Ukraine. Manafort has defended his foreign business dealings. He told the New York Times this month that he "never knowingly spoke to Russian intelligence officers."

December

President Barack Obama ordered the U.S. intelligence community to review Russia's hacking operation on Dec. 9, and produce a public report before his term ended. Three days later, Senate Majority Leader Mitch McConnell (R-Ky.) announced the Senate would launch an investigation as well.

"The Russians are not our friends," McConnell said.

McConnell's announcement came on the same day that House and Senate lawmakers from both parties called for an investigation into the matter.

On Dec. 29, the Obama administration sanctioned Russia after determining based on intelligence evidence that the country hacked the Democratic Party in an effort to influence the U.S. election. The Obama administration expelled 35 Russian intelligence officials from the U.S., and closed clandestine Russian intelligence-gathering facilities in New York and Maryland.

President Barack Obama addressed Russia's interference in the U.S. election during a press conference on December 16, 2016. Photo by REUTERS/Jonathan Ernst

Mr. Obama also signed an executive order sanctioning nine individuals and groups for election-related hacking. He said his administration would take other actions against Russia, some of which would not be made public. Obama said the actions were a "response to the Russian government's aggressive harassment of U.S. officials and cyber operations aimed at the U.S. election."

READ MORE: Who is Lt. Gen. Michael Flynn?

According to news reports that emerged weeks later, shortly before they were announced, incoming national security adviser Michael Flynn discussed the sanctions with Sergey Kislyak, Russia's ambassador to the United States. U.S. intelligence agencies intercepted the communications. Flynn later told Vice President Mike Pence that he had not discussed the sanctions, setting off the chain of events that led to his resignation.

2017:

Jan. 6

The Office of the Director of National Intelligence released a declassified version of its report to Obama on Russia's role in the election. The report concluded with "high confidence" — intelligence community speak for virtual certainty — that Russian President Vladimir Putin ordered the hacking operation in an effort to hurt Clinton's campaign and help elect Trump. The report also found that the GRU, Russia's military intelligence service, gave the information it obtained from the DNC and Clinton campaign's emails to WikiLeaks.

The report concluded with 'high confidence' — intelligence community speak for virtual certainty — that Russian President Vladimir Putin ordered the hacking operation.

Jan. 10

The leaders of the Senate Intelligence Committee announced that the panel would conduct an inquiry into Russia's role in the election. In a joint statement issued on Jan. 13, Chairman Richard Burr (R-N.C.) and Vice Chairman Mark Warner (D-Va.) said the U.S. intelligence community's October 2016 report, which concluded that Russia had meddled in the election, "raised profound concerns."

Burr and Warner said the panel's investigation would include a review of the U.S. intelligence assessment released last October, and an inquiry into "any intelligence regarding links between Russia and individuals associated with political campaigns." The senators also said they planned to hold hearings, and interview current and former administration officials. The announcement also said the committee would potentially issue subpoenas "if necessary to compel testimony."

Jan. 15

Vice President Mike Pence said in interviews on Face the Nation and Fox News Sunday that Flynn did not discuss the U.S. sanctions against Russia in conversations with Kislyak before Trump took office. (Subsequent reporting suggests that Pence made the assertion based on what Flynn had told him about the conversations). One week later, in his first full press briefing on Jan. 23, White House press secretary Sean Spicer also said the sanctions hadn't come up in Flynn's phone calls with the Russian ambassador.

Under the Logan Act, it's illegal for private citizens to correspond with foreign governments or officials to try and influence foreign policy. Flynn was a top foreign policy adviser to Trump during the campaign, and the national security adviser-designate during the transition. But he remained a private citizen until formally taking over as national security adviser after Trump was sworn in as president.

Vice President Mike Pence speaks Feb. 18 at the Munich Security Conference. Pence learned that Flynn had discussed sanctions with a Russian official two weeks after Trump found out. Photo by REUTERS/Michael Dalder

Late January

The FBI interviewed Flynn about the phone calls "just days" after he took office as national security adviser in late January, according to a report by the New York Times. The Times reported that U.S. intelligence agencies recorded the phone calls between Flynn and Kislyak, as part of their routine surveillance of Kislyak and other Russian officials.

According to the Times report, Sally Yates, the acting attorney general, contacted White House counsel Don McGahn on Jan. 26 and told him there was a disparity between what Flynn had said in his call with Kislyak and the claim from administration officials that sanctions had not been discussed.

Feb. 2

The Senate Judiciary Subcommittee on Crime and Terrorism announced it was launching a separate probe into Russia's election hacking. Chairman Lindsey Graham (R-S.C.) and Ranking Member Sheldon Whitehouse (D-R.I.) said in a joint statement: "Our goal is simple – to the fullest extent possible we want to shine a light on Russian activities to undermine democracy."

Feb. 9

The Washington Post published an explosive story showing Flynn had talked about the sanctions in his calls with the Russian ambassador. The Post's reporting also said that Flynn's communication with Kislyak started before Trump won the election on Nov. 8. The story noted that Flynn's calls also raised questions inside the Obama administration over whether he violated the law.

In his resignation letter, Flynn wrote: 'I inadvertently briefed the Vice President Elect and others with incomplete information regarding my phone calls with the Russian Ambassador.'

Feb. 13

Michael Flynn resigned. In his resignation letter, Flynn wrote: "I inadvertently briefed the Vice President Elect and others with incomplete information regarding my phone calls with the Russian Ambassador." Flynn said he apologized to Pence and Trump. But Flynn also defended his actions, saying that "such calls are standard practice," and he did not admit to any wrongdoing.

Michael Flynn walks down the White House colonnade Feb. 10, three days before resigning as national security adviser. Photo by REUTERS/Jim Bourg


Feb. 14

Sean Spicer said in a press briefing that Trump learned of Flynn's phone calls two weeks before his resignation. The Vice President's office said Pence found out about the true content of the calls — and the fact that Flynn misled him — through reading about it in media reports, roughly 14 days after Trump found out.

WATCH: Trump did not instruct Flynn to talk about Russia sanctions, Spicer says

According to a New York Times story published the same day, U.S. intelligence agencies intercepted communications between several people associated with Trump or his campaign and Russian government officials during the election.

Feb. 16

Trump defended Flynn's actions in a lengthy news conference at the White House. When asked if any officials with his campaign had communicated with Russia during the election, Trump said, "nobody that I know of." Trump also called news reports about his campaign's ties to Russia "fake news," and claimed that he did not have any connections to the country. "Russia is a ruse. I have nothing to do with Russia. Haven't made a phone call to Russia in years," Trump said.

Feb. 17

FBI Director James Comey met with the Senate Intelligence Committee panel investigating Russia's role in the 2016 election. The briefing was not open to the press, and few details from the meeting emerged. Afterwards, Sen. Mark Warner (D-Va.) told Politico that he and Chairman Richard Burr (R-N.C.) were trying to ensure that the investigation does not "default to a partisan food fight that doesn't serve the public interest."

March 1

The Washington Post reported that Attorney General Jeff Sessions met with Kislyak, Russia's U.S. ambassador, last September, when Sessions was a member of the Senate Armed Services Committee and a top national security adviser on Donald Trump's campaign. The Post also reported that Sessions spoke briefly with Kislyak during the Republican National Convention in July. The reporting appeared to contradict Sessions' written and oral testimony at his confirmation hearings, when he said he did not have contact with Russian officials during the 2016 election.

A Justice Department spokesperson said Wednesday night that Sessions met with ambassadors from many countries last year, including Russia, as part of his work as a member of the Armed Services Committee.

In a statement, Sessions said: "I have never met with any Russian officials to discuss issues of the campaign. I have no idea what this allegation is about. It is false."

March 2

As news of Sessions' meetings with Kislyak broke, it raised questions about Department of Justice and FBI investigations into Russia's involvement in the U.S. election.

On Thursday, a growing chorus of House and Senate Democrats called on Sessions to resign from his position atop the agencies tasked with investigating Russia's election interference.

"Sessions is not fit to serve as the top law enforcement officer of our country and must resign. There must be an independent, bipartisan, outside commission to investigate the Trump political, personal and financial connections to the Russians," House Minority Leader Nancy Pelosi (D-Calif.) said in a statement.

Republicans on Thursday stopped short of calling for Sessions' resignation. But some GOP lawmakers said Sessions should recuse himself from the federal investigations into Russia.

"AG Sessions should clarify his testimony and recuse himself," House Oversight and Government Reform Committee Chairman Jason Chaffetz (R-Utah), wrote on Twitter.

U.S. Attorney General Jeff Sessions pauses at a news conference Mar. 2 at the Justice Department in Washington, D.C. Photo by REUTERS/Yuri Gripas.

In response to the growing controversy, Sessions held a news conference on March 2 to announce that he would recuse himself from any investigations into the 2016 campaign, including probes that involve Russia's role in the election.

WATCH: Jeff Sessions recuses himself from Russia investigation

Sessions said ethics officials at the Justice Department told him "that since I had involvement with the campaign, I should not be involved in any campaign investigation."

Sessions also addressed the testimony he gave at his confirmation hearings. "In retrospect, I should have slowed down and said I did meet one Russian official a couple times, and that would be the ambassador," he said.

The same day, Carter Page, a former Trump campaign adviser, acknowledged he did have contact with a Russian official during the election. On March 2, Page said he met with Russia's U.S. ambassador during the Republican National Convention in Cleveland last July. It was a reversal of a February interview with PBS NewsHour's Judy Woodruff, during which Page said he had not met with Russian officials during the race. Page made a similar claim to other news outlets.

March 4

In a series of early-morning tweets, President Trump accused former President Barack Obama of wiretapping Trump Tower during the 2016 race, without offering any evidence.

"Terrible! Just found out that Obama had my "wires tapped" in Trump Tower just before the victory. Nothing found. This is McCarthyism!" Trump wrote.

In a second tweet, Trump wondered if it was legal for Obama to be "wire tapping" him during the election. In another third tweet, Trump wrote: "I'd bet a good lawyer could make a great case out of the fact that President Obama was tapping my phones in October, just prior to Election!"

The tweets caused an immediate firestorm, forcing White House officials to defend the president's allegations. Democrats and some Republicans criticized the president for leveling such a serious claim without backing it up.

READ MORE: Trump enlists Congress, ex-intel chief denies wiretapping

In the days that followed, former Obama administration officials denied Trump's claims. "There was no wiretap against Trump Tower during the campaign conducted by any part of the National Intelligence Community," former Director of National Intelligence James Clapper said.

A spokesman for Obama also issued a response denying Trumps' allegation. "Neither President Obama nor any White House official ever ordered surveillance on any US citizen. Any suggestion otherwise is simply false," the spokesman said.

March 13

After several days of defending the president's tweets, White House press secretary Sean Spicer took a different approach. At a press briefing, Spicer argued that by putting the word wiretapping in quotation marks in his tweets, Trump had been referring to surveillance efforts in general, and not necessarily to a specific instance in which his phone calls were recorded.

March 15
Rep. Devin Nunes, the chairman of the House Intelligence Committee, said he did not think that Trump Tower was wiretapped. But Nunes said it was possible that incidental collection of Trump campaign conversations could have taken occured while U.S. agencies were conducting wider surveillance operations.

READ MORE: House Intelligence Committee says they have seen no evidence supporting Trump's wiretapping claims

March 20

FBI Director James Comey testified at the House Intelligence Committee's first public hearing on its investigation into links between Russia and the Trump campaign. Comey confirmed that the agency was conducting an investigation into Russia's role in the U.S. election, and any possible links to Trump's campaign. It's the FBI's policy not to confirm existing investigations, making Comey's admission all the more significant.

Comey also dismissed Trump's wiretapping claim. "I have no information that supports those tweets, and we have looked carefully inside the FBI," he said.

READ MORE: Comey: FBI is investigating possible links between Russia, Trump associates

Comey was joined by National Security Agency Director Adm. Michael Rogers, who also said under oath at the hearing that his agency did not have information supporting Trump's claim.
"I have seen nothing on the NSA side that we have engaged in such activity, nor that anyone ever asked us to engage in such activity," Rogers said.

March 22

Chairman of the House Intelligence Committee Devin Nunes (R-Calif) questions FBI Director James Comey and National Security Agency Director Mike Rogers during a hearing into alleged Russian meddling in the 2016 U.S. election. Photo by REUTERS/Joshua Roberts.

Nunes told reporters that sources had shared documents with him showing that the Trump campaign's communications had been incidentally collected in a wider surveillance effort. Nunes then briefed the president at the White House on his committee's investigation. Afterwards, Nunes held a press conference on White House grounds. Later that day, Trump said he felt "somewhat" vindicated by Nunes' announcement.

In making the announcement, Nunes did not name his sources. He also did not share his findings with other members of the House Intelligence Committee, including the ranking member, Rep. Adam Schiff (D-Calif). Nunes' unusual trip to the White House and subsequent press briefing drew instant criticism. Schiff and other Democrats expressed doubts that Nunes was conducting an independent investigation.

READ MORE: Schiff calls on Nunes to recuse himself from Russia probe

Several Democrats — and later at least one Republican — called on Nunes to recuse himself from leading the investigation.

The clamor for Nunes' recusal grew louder when reports surfaced days later that Nunes had gone to the White House on March 21 — the day before he briefed the president and the press — to meet with his sources, and that Nunes' information had come from White House officials.

On March 23, Nunes said he regretted initially keeping members of the intelligence committee in the dark. But in the days that followed, Nunes resisted calls for his recusal, and GOP leaders backed him up.

READ MORE: Devin Nunes faces growing pressure to recuse himself from Russia probe

March 25

Carter Page and Roger Stone, two former Trump campaign advisers, said they would speak to the House Intelligence Committee conducting an investigation into Russia's role in the 2016 election. Stone defended his actions, saying he did not do anything wrong during the campaign.

Page sent a letter to the House panel the day before asking to "set the record straight" about his activities during the election. The offer came weeks after Page admitted to speaking with a Russian official during the RNC in Cleveland.

March 27

President Donald Trump gives a thumbs-up Mar. 15 as he and White House Senior Advisor Jared Kushner depart the White House in Washington, D.C. Photo by REUTERS/Kevin Lamarque.

The New York Times reported that the Senate Intelligence Committee planned to question Jared Kushner, a senior adviser to President Trump and his son-in-law, as part of its investigation into Russia and its links to Trump's campaign. During the transition, Kushner arranged meetings with Sergey Kislyak, Russia's ambassador to the U.S. and a top Russian banking official.

The committee's leaders, Chairman Richard Burr (R-N.C.) and Vice Chairman Mark Warner (D-Va.), said a date for Kushner's testimony had not yet been set. The news was bad timing for the White House. The same day, President Trump announced that Kushner would lead a task force aimed at streamlining government operations.

March 28

Nunes canceled a planned House Intelligence Committee hearing on its investigations into Russia and possible ties to Trump's campaign. Sally Yates, the former acting attorney general, had been scheduled to testify. The Washington Post published a story saying the Trump administration tried to block Yates from testifying, something the White House denied.

WATCH: Spicer says White House has 'no problem' with former acting AG Sally Yates testifying on Russia

March 30

Senate Intelligence Committee Chairman Sen. Richard Burr (R-NC), accompanied by Senator Mark Warner (D-VA), vice chairman of the committee, speaks at a news conference to discuss their probe of Russian interference in the 2016 election on Capitol Hill in Washington, D.C. REUTERS/Aaron P. Bernstein.

The Senate Intelligence Committee held its first public hearing on its own investigation into Russia's role in the election. The panel's leaders, Chairman Richard Burr (R-N.C.) and Vice Chairman Mark Warner (D-Va.), reiterated their intent to conduct an independent, bipartisan investigation.

READ MORE: First public Senate Intelligence hearing on Russia probe highlights influence of disinformation

Michael Flynn also resurfaced in the news March 30, when Wall Street Journal reported that the former national security adviser had offered to testify before Congress in exchange for immunity from being prosecuted. Multiple news outlets have reported that House and Senate lawmakers leading the investigations have not yet accepted Flynn's offer.

March 30

Flynn offered to speak with the FBI and congressional investigators about the Trump campaign's potential links to Russia in exchange for immunity. Flynn "has a story to tell, and he very much wants to tell it, should the circumstances permit," his attorney Robert Kelner said in a statement.

"No reasonable person, who has the benefit of advice from counsel, would submit to questioning in such a highly politicized, witch hunt environment without assurances against unfair prosecution," Kelner said in the statement.

April 11

The Washington Post reported that the FBI and Department of Justice received a warrant from the Foreign Intelligence Surveillance Court in the summer of 2016 to "monitor the communications" of then-Trump campaign adviser Carter Page. At the time, the agencies believed there was evidence that Page was speaking with Russian officials and potentially acting on their behalf.

The same day, the inspector general of the Defense Intelligence Agency wrote a letter to Rep. Jason Chaffetz (R-Utah) — the chairman of the House Oversight and Government Reform Committee — informing him that the agency had launched an investigation into Flynn. The agency said it was probing whether Flynn obtained approval to receive payments from foreign governments.

April 25

Chaffetz said Flynn may have violated the law by not seeking approval for, or properly disclosing, payments he received from sources tied to Russia and Turkey. "I see no data to support the notion that General Flynn complied with the law," Chaffetz told reporters.

May 1

Page told Fox News that he was cooperating with the Senate's investigation into potential ties between Russia and Trump's campaign. The previous week, the Senate Intelligence Committee had written a letter to Page requesting that he provide information on his meetings and communication with Russian officials from mid-2015 to January 20, 2017, the day Trump was sworn into office.

May 4

In a letter to the Senate Intelligence Committee, Page appeared to turn down the panel's request for information on his contacts with Russian officials. Page wrote that U.S. intelligence agencies already had the information as part of their surveillance of his communications, and requested the Senate panel disclose more information about its inquiry. In the letter, Page called the Senate panel's investigation an "ongoing witch hunt."

May 5

The Washington Post reported that after the 2016 election, members of Trump's transition team warned Flynn that U.S. intelligence agencies were likely monitoring the conversations of Sergey Kislyak, Russia's U.S. ambassador. One month later, in late December 2015, Flynn spoke with Kislyak about the Obama administration's sanctions against Russia.

May 8

Sally Yates, the former acting Attorney General, is scheduled to appear before a Senate hearing investigating possible links between Trump's campaign and Russia. Yates is expected to testify that she warned the Trump White House about Flynn's links to Russia. Former Director of National Intelligence James Clapper is also slated to testify at the hearing, before the Senate Judiciary Subcommittee on Crime and Terrorism.

Correction: A second reference to Senator Richard Burr of North Carolina identified him as a Democrat. Burr is a Republican.

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