WATCH: White House national security adviser says U.S. is pressing for the release of reporter who has spent 100 days in Russian jail

WASHINGTON (AP) — White House national security adviser Jake Sullivan on Friday said the U.S. has been in contact with Russian officials to press for the release of Wall Street Journal reporter Evan Gershkovich as Friday marked the 100th day of the journalist being detained by the Russian government.

Watch the briefing in the player above.

Sullivan said he also spoke with Gershkovich’s family representatives and Wall Street Journal officials on Friday about the status of the case and the administration’s efforts to win the reporter’s release.

The Kremlin earlier this week suggested that it was open to a possible prisoner exchange that could involve Gershkovich, but it underscored that such talks must be held out of the public eye.

“I do not want to give false hope,” Sullivan told reporters. “What the Kremlin said earlier this week is correct. There have been discussions. But those discussions have not produced a clear pathway to a resolution, and so I cannot stand here today and tell you that we have a clear answer to how we are going to get Evan home.”

The U.S. ambassador to Moscow, Lynne Tracy, on Monday was allowed to visit Gershkovich for the first time since April.

WATCH: Wall Street Journal publisher discusses Russia’s charges against Evan Gershkovich

Gershkovich was arrested on espionage charges in the city of Yekaterinburg while on a reporting trip. He is being held at Moscow’s Lefortovo prison, notorious for its harsh conditions. A Moscow court last week upheld a ruling to keep him in custody until Aug. 30.

Gershkovich and his employer deny the allegations, and the U.S. government has declared him to be wrongfully detained. His arrest rattled journalists in Russia. Authorities there have not provided any evidence to support the espionage charges.

White House press secretary Karine Jean-Pierre reiterated the U.S. stance that the detention of Gershkovich was baseless. She reiterated the administration’s call for the immediate release of Gershkovich and Paul Whelan, a Marine Corps veteran who has been detained in Russia on espionage charges for four years.

“Our message to Evan and Paul is this: Keep the faith. We won’t stop until you are home,” Jean-Pierre said.