President Vladimir Putin said on Thursday that the fate of 24 Ukrainian sailors held in Russia since last year must be linked to the release of Russian citizens held in Ukraine whom Moscow wants to see freed.
Putin's comments marked a departure from the Kremlin's insistence that the sailors must be put on trial and that their case must be properly investigated before any discussion of their possible release.
The Russian navy captured the Ukrainian sailors and their three vessels in the Kerch Strait, which links the Black Sea and the Sea of Azov, on Nov. 25, 2018, after opening fire on them.
Moscow accuses them of illegally entering Russian waters, something Kiev denies. The United States and European Union have urged Russia to release the men.
"Issues like this one should not be resolved in isolation," Putin said at his annual televised question-and-answer session.
"Before resolving these issues, we should think about how to resolve the fate of people we are concerned about, including Russian citizens who are in a similar situation in Ukraine," he said.
The Hamburg-based International Tribunal for the Law of the Sea (ITLOS) said last month that Moscow should release the sailors immediately and that both countries should refrain from action that might aggravate the dispute.
The Kremlin rebuffed the call, saying the court lacked the jurisdiction to make such a ruling.