WASHINGTON (AP) — Secretary of State Antony Blinken said he spoke to Russian Foreign Minister Sergey Lavrov by phone on Friday and urged Moscow to accept a U.S. offer to release WNBA star Brittney Griner and another American detainee, Paul Whelan.

It was Blinken’s first talk with his Russian counterpart since before Russia’s invasion of Ukraine in February.

Blinken did not provide details of Lavrov’s response to what he had previously called a “substantial proposal” for Russia to release Whelan and Griner. Blinken had publicly requested the call and revealed the existence of the offer to Russia, which people familiar with say involves a swap for Whelan and Griner with convicted Russian arms dealer Viktor Bout.

Blinken described the call as “a frank and direct conversation” centered primarily on the proposal for the release of the Americans.

“I urged Foreign Minister Lavrov to move forward with that proposal. I can’t give you an assessment of whether that is any more or less likely,” he said.

Blinken also said he had pressed Lavrov on the importance of Russia following through on an agreement to allow Ukrainian grain shipments to leave the Black Sea and warned him of consequences should Moscow move ahead with suspected plans to annex portions of eastern and southern Ukraine.

Blinken said he told Lavrov that the world will “never recognize” any annexation of Ukrainian territory, which he said would “will result in significant additional costs for Russia.”

He declined to comment on how Lavrov replied to his messages.

“I don’t want to characterize any of Foreign Minister Lavrov’s responses,” Blinken said.

© 2022 Associated Press All rights reserved.