Rescuers work at the crash site of the Ukrainian Armed Forces' Antonov aircraft in Kyiv region

What to know as Russia attacks Ukraine

WARSAW, Poland (AP) — Russian troops launched a broad assault on Ukraine from three sides Thursday, an attack that brought explosions before dawn to the country’s capital, Kyiv, and other cities.

Ukraine’s leadership said at least 40 people had been killed so far in what it called a “full-scale war” targeting the country from the east, north and south. It said Russia’s intent was to destroy the state of Ukraine, a Western-looking democracy intent on moving out of Moscow’s orbit.

As civilians piled into trains and cars to flee, NATO and European leaders rushed to respond, if not directly in Ukraine, with strong financial sanctions against Russia and moves to strengthen their own borders.

Here are the things to know about the conflict over Ukraine and the security crisis in Eastern Europe:

Putin makes his move

In a televised address as the attack began, Russian President Vladimir Putin said it was needed to protect civilians in eastern Ukraine, where Ukrainian forces and Russia-backed separatists have been fighting for almost eight years.

The U.S. had predicted Putin would falsely claim that the rebel-held regions were under attack to justify an invasion.

The Russian leader warned other countries that any attempt to interfere in Ukraine would “lead to consequences you have never seen in history” — a dark threat implying Russia was prepared to use its nuclear weapons.

Putin accused the U.S. and its allies of ignoring Russia’s demands to block Ukraine from ever joining NATO and offer Moscow security guarantees.

Putin said Russia does not intend to occupy Ukraine but plans to “demilitarize” it. Soon after his address, explosions were heard in the cities of Kyiv, Kharkiv and Odesa. Russia said it was attacking military targets.

He urged Ukrainian servicemen to “immediately put down arms and go home.”

Ukraine’s border guard agency said the Russian military attacked from neighboring Belarus, unleashing a barrage of artillery. The agency said Ukrainian border guards fired back. Russian troops had been in Belarus, a Moscow ally, for what Russian and Belarusian officials had described as joint military drills.

The West reacts quickly

World leaders decried the start of an invasion that could cause massive casualties, topple Ukraine’s democratically elected government and threaten the post-Cold War balance.

NATO Secretary General Jens Stoltenberg called Russia’s attack “a brutal act of war” and said Moscow had shattered peace on the European continent.

U.S. President Joe Biden said Putin “has chosen a premeditated war that will bring a catastrophic loss of life and human suffering.”

In Lithuania, a small Baltic nation and NATO member that borders Russia’s Kaliningrad region to the southwest, Belarus to the east, Latvia to the north and Poland to the south. President Gitanas Nauseda signed a decree declaring a state of emergency. The country’s parliament was expected to approve the measure later in the day.

British Prime Minister Boris Johnson said Putin has “unleashed war in our European continent” and Britain “cannot and will not just look away.”

“Our mission is clear: diplomatically, politically, economically and eventually militarily, this hideous and barbaric venture of Vladimir Putin must end in failure,” Johnson said.

German Chancellor Olaf Scholz sharply condemned Russia’s attack, calling it “a terrible day for Ukraine and a dark day for Europe.”

Japanese Prime Minister Fumio Kishida said: “This Russian invasion stands to put at risk the basic principle of international order that forbids one-sided action of force in an attempt to change the status quo.”

Ukraine’s president urges calm

Residents of Ukraine’s capital, Kyiv, could be heard shouting in the streets when the first explosions sounded. Cars nonetheless circulated in the streets during the early morning commute.

President Volodymyr Zelenskyy issued a video statement declaring martial law. He told Ukrainians that the United States was gathering international support to respond to Russia. He urged residents to remain calm and to stay at home.

Zelenskyy had repeatedly appealed to Putin in recent days to pursue a diplomatic path instead of taking military action. He urged world leaders Thursday to provide defense assistance and help protect Ukraine’s airspace from Russia

Mykhailo Podolyak, a presidential adviser, said fighting was taking place Thursday along practically the entire perimeter of the country’s border.

World markets fall

World stock markets plunged and oil prices surged by nearly $6 per barrel after Putin launched Russian military action in Ukraine.

Market benchmarks tumbled in Europe and Asia and U.S. futures were sharply lower. Brent crude oil jumped to over $100 per barrel Thursday on unease about possible disruption of Russian supplies.

The ruble sank 7.5% to more than $87 to the U.S. dollar. Earlier, Wall Street’s benchmark S&P 500 index fell 1.8% to an eight-month low after the Kremlin said rebels in eastern Ukraine asked for military assistance.

Putin’s declaration overtakes emergency U.N. Security Council session

At an emergency meeting of the U.N. Security Council called by Ukraine that opened just before Putin’s announcement, U.N. Secretary-General Antonio Guterres told Putin: “Stop your troops from attacking Ukraine. Give peace a chance. Too many people have already died.”

Guterres later pleaded with Putin, “In the name of humanity, bring your troops back to Russia.”

When will the West impose more sanctions

Ukraine’s forces are no match for Moscow’s military might, so Kyiv is counting on other countries to hit Russia hard — with sanctions.

Biden on Wednesday allowed sanctions to move forward against the company that built the Russia-to-Germany Nord Stream 2 gas pipeline and against the company’s CEO.

Biden waived sanctions last year when the project was almost completed, in return for an agreement from Germany to take action against Russia if it used gas as a weapon or attacked Ukraine. Germany said Tuesday it was indefinitely suspending the pipeline.

Biden said more sanctions would be announced on Thursday.

Meanwhile, the European Union planned the “strongest, the harshest package” ever, to be considered at a summit on Thursday, according to EU foreign policy chief Josep Borrell.

“A major nuclear power has attacked a neighbor country and is threatening reprisals of any other states that may come to the rescue,” Borrell said.

“This is not only the greatest violation of international law, it’s a violation of the basic principles of human co-existence. It’s costing many lives with unknown consequences ahead of us. The

European Union will respond in the strongest possible terms.”

What sanctions were under U.S. consideration if Russia invaded?

The Biden administration had made clear it was holding tough financial penalties in reserve in case of just such a Russian invasion.

The U.S. hasn’t specified just what measures it will take now, although administration officials have made clear that all-out sanctions against Russia’s major banks are among the likely options. So are export limits that would deny Russia U.S. high tech for its industries and military.

Another tough measure under consideration would effectively shut Russia out of much of the global financial system.

China’s support for Russia

China’s customs agency on Thursday approved imports of wheat from all regions of Russia, a move that could help to reduce the impact of possible Western sanctions.

China’s populous market is a growth area for other farm goods suppliers, but Beijing had barred imports until now from Russia’s main wheat-growing areas due to concern about possible fungus and other contamination.

Russia is one of the biggest wheat producers, but its exports would be vulnerable if its foreign markets block shipments in response to its attack on Ukraine.

Thursday’s announcement said Russia would “take all measures” to prevent contamination by wheat smut fungus and would suspend exports to China if it was found.

Ukraine sees more cyberattacks

The websites of Ukraine’s defense, foreign and interior ministries were unreachable or painfully slow to load Thursday morning after a punishing wave of distributed-denial-of-service attacks as Russia struck at its neighbor.

In addition to DDoS attacks on Wednesday, cybersecurity researchers said unidentified attackers had infected hundreds of computers with destructive malware, some in neighboring Latvia and Lithuania.

Officials have long expected cyberattacks to precede and accompany any Russian military incursion.

Associated Press writers around the world contributed to this report.