A Ukrainian court has convicted two alleged Russian special forces soldiers of crimes including terrorism and sentenced them to 14 years in jail.
The pair – Yevgeny Yerofeyev and Alexander Alexandrov – were captured in eastern Ukraine last May.
Russia denies sending troops to the region and has said the men were volunteers who had left active service.
A fragile ceasefire is in place in eastern Ukraine between the army and pro-Russian rebels.
The court in Kiev found Yerofeyev and Alexandrov guilty of waging an “aggressive war” against Ukraine, committing a terrorist act and using weapons to provoke an armed conflict, the Interfax news agency reported.
The two men had denied the charges. Moscow said it would do everything in its power to bring them home, Russian state media reported.
Last month a Russian court found a Ukrainian, Nadiya Savchenko, guilty of charges relating to the deaths of two Russian journalists. She was jailed for 22 years.
A pilot by training, she was accused of directing artillery fire that killed the journalists.
Her trial received widespread international condemnation and she declared a hunger strike in protest against her treatment.
There has been speculation that she may be swapped for the two Russians captured in eastern Ukraine.
During a televised appearance last week, Russian President Vladimir Putin said that the government in Moscow was in contact with the Ukrainian leadership over the issue.