US Secretary of State Mike Pompeo on Thursday urged his Russian counterpart Sergei Lavrov to "immediately release" jailed Ukrainian filmmaker Oleg Sentsov, who has been on hunger strike for more than three months.
Sentsov, a 42-year-old Kremlin opponent, was arrested in Crimea after Moscow's 2014 annexation of the peninsula and has been languishing in a Russian Artic prison with little hope of release.
He announced the hunger strike in May demanding the release of all Ukrainian political prisoners being held in Russia.
Pompeo "noted our concerns about Sentsov's health and urged Russia to immediately release Sentsov and all Ukrainian political prisoners," State Department spokeswoman Heather Nauert said in a readout of the call.
The case has garnered wide international attention.
In the Czech Republic, filmmakers this week said they were launching a rotating hunger strike in solidarity with the director.
And French newspaper Le Monde carried a plea signed by dozens of figures from the world of culture calling for his release, saying "Oleg Sentsov could die any minute."
Sentsov was convicted of planning arson attacks on pro-Moscow party offices in Crimea after Russia annexed the peninsula from Ukraine in 2014.
He had also taken part in the Maidan protests in Kiev during the winter of 2013-2014 that culminated in Moscow-backed president Viktor Yanukovych fleeing the country.
Nauert said Pompeo and Lavrov had also discussed the situation in Syria, including military activities in Idlib province, which borders Turkey.
President Bashar al-Assad has his sights set on retaking control of Idlib, currently held by rebels.
Pompeo asked Lavrov "to support efforts in the Organization for the Prohibition of Chemical Weapons, as well as efforts to hold the Syrian regime accountable for its use of chemical weapons," Nauert said.