The BorgWarner employee who has been detained in Russia since 2018 says he thinks progress is being made toward his release.

“I remain positive and confident on a daily basis that the wheels are turning,” Whelan said in a phone call to CNN last week from his prison camp. “I just wish they would turn a little bit more quickly.”

Whelan, a U.S. Marine who was BorgWarner’s security director, was sentenced in 2020 to 16 years in prison on spying charges that he has denied. He was arrested in December 2018 while attending a wedding in Moscow after receiving a flash drive with government secrets that he says he thought contained holiday pictures.

He told CNN that he’s more confident in the U.S. government’s efforts to bring him home than he was last December, when Russia released WNBA player Brittney Griner.

More recently, however, Russia arrested U.S. journalist Evan Gershkovich on charges of espionage, another case that the White House is working to resolve.

“I have been told that I won’t be left behind, and I have been told that although Evan’s case is a priority, mine is also a priority, and people are cognizant of the fact that this is having an extremely negative impact on me and my family,” Whelan said. “And I’m told that the government is working tirelessly to get me out of here and to get me home so they can then focus effort on Evan and his case.”

Whelan said he was experiencing “the usual aches and pains of forced labor … and poor living conditions” but trying to remain optimistic about his prospects of going home.

“There will be an end to this, and I hope it’s coming sooner than later, but it is depressing on a daily basis going through this,” he said.

President Joe Biden, at the White House Correspondents’ Dinner last month, said his administration would continue fighting for Whelan “until we get him home,” while the U.S. State Department has said it has “no higher priority” than getting Whelan and Gershkovich released.