An Iranian-American journalist sentenced to 10 years in a notorious Tehran prison called on Washington to provide medical help for him and other US detainees, CBS News reported Friday. Reza Valizadeh, who holds both Iranian and US citizenship and worked for US-funded Persian-language Radio Farda, is in prison on charges of collaborating with a hostile government, according to his lawyer. A voice message from the journalist obtained by CBS News comes amid a shaky truce as Tehran and Washington conduct slow-moving negotiations to resolve a war launched by President Donald Trump in February. Valizadeh said in the two-minute recording that he and three other Americans held at Tehran's Evin prison were sick and being denied medical treatment. "While the four of us are suffering from various diseases and are deprived from real medical services, the US government could have at least demanded real medical services for us in exchange for the release of Iranian sailors," he says. "Even if treating our diseases is a big demand, it would have at least asked the Iranian authorities to reduce not all the physical pressure and mental torture against us in captivity, but at least some of it." AFP was not able to verify the authenticity of the recording. CBS News said the recording was recent and had been made after Iranian authorities loosened wartime communication restrictions last week. Valizadeh's lawyer Ryan Fayhee told CBS News that Valizadeh was suffering from persistent coughing, back pain and dental problems. "He's survived an airstrike on the prison, he survived the prison itself," Fayhee said, referring to an Israeli strike which damaged parts of the facility in June last year. The United States said in 2024 it was aware of Valizadeh's detention and called on Iran to free him. Rights groups have denounced conditions in Iran's prisons, where detainees suffer from overcrowding and shortages of food, water, hygiene supplies, medicine and medical care.