Secretary of State Antony Blinken on Friday spoke with his Russian counterpart about efforts to secure the release of WNBA star Brittney Griner and Paul Whelan.

The Associated Press reported Blinken urged Russian Foreign Minister Sergey Lavrov to accept a deal to obtain the release of Griner and Whelan, an American citizen who is serving a 16-year prison sentence after his conviction for spying.

American officials have reportedly expressed a willingness to release Viktor Bout, a Russian arms dealer who is serving a 25-year prison sentence in the U.S., as part of a prisoner swap.