Brittney Griner Aug 8, 2021; Saitama, Japan; United States centre Brittney Griner (15) reacts to a call against Japan in the women’s basketball gold medal match during the Tokyo 2020 Olympic Summer Games at Saitama Super Arena. Mandatory Credit: James Lang-USA TODAY Sports

The administration of United States President Joe Biden is working to free imprisoned WNBA star Brittney Griner and former Marine Paul Whalen from Russian custody, CNN reported Tuesday.

A senior administration official told CNN that Russia and the United States had communicated “as recently as within past days.”

Griner celebrated her 32nd birthday in Russian custody on Friday. An aide to Vladimir Putin said earlier this week that Griner’s release from her sentence for trafficking hashish oil is not a current priority for the regime.

The administration official described the conversations to CNN as “pretty persistent.” The official contended that the United States had yet to receive a serious counterproposal from Russia.

“We have worked hard to try to demonstrate the sorts of things that could well be the basis for resolving this and each time we have articulated that it’s been met not with a serious counteroffer,” the official told CNN.

The official contended Russia countered with “something not in our control, not in our ability to deliver” but refused to talk specifics with CNN.

“They’re not non-responsive. I would say that they continue to respond with something that they know not to be feasible or available,” the official said of the Russian response.

Griner faces nine years in Russian custody. Her official appeal hearing is scheduled for Oct. 25.