(NewsNation) — The former U.S. Marine detained for the last five years is losing weight and living “a very depressing life,” his brother said.

U.S. Marine veteran Paul Whelan has been wrongfully detained in Russia since 2018; he was accused of spying. The Whelan family has been working with U.S. officials closely as they continue to negotiate his release.

Paul Whelan’s brother, David, said he spoke to Paul a few days ago is “doing the best he can” and taking it “one day at a time.”

“The prison has cut back on food, he’s lost a lot of weight,” David Whelan told NewsNation’s Markie Martin on Tuesday on “Morning in America.” “They aren’t even able to make as many clothes in the factory, because the Ukraine war has limited the supplies. So they’re idle a lot. It’s just a very depressing life.”

David Whelan said Paul receives regular visits from U.S. diplomats in Mordovia, who ensure his well-being and that he receives food and medicine.

David Whelan said his family maintains hope that U.S. officials are “successful in making a concession” that brings Paul home.

“On a day like today, when you know that America has its freedom, and Americans have it,” David Whelan said. “At least Paul has that to look forward to that at some point, he will be coming back to our free country and people in Russia really can’t understand what it is to have the rights and freedoms not always perfect, but the opportunity, the possibility of the freedom, and I think Paul is sustained by that.”