Ukraine’s Presidential Humanitarian Envoy at the Minsk peace talks regarding the war in Donbas MP Iryna Herashchenko says Ukraine has contacted Russia regarding the exchange of prisoners countless time. According to StopFake, Herashchenko said that she has personally sent letters to Russian representatives regarding Russian prisoners in Ukraine three times. She mentions that she has raised the issue at Minsk meetings many times and notes that Russian consuls have never visited detained Russians and they continue to propagate the lie that Russian military personnel, captured or not, are simply not in Ukraine.

The Trilateral Contact Group on Ukraine is a group of representatives from Ukraine, the Russian Federation, and the Organization for Security and Co-operation in Europe. On August 23 it informed that the Humanitarian Working group had considered issues related to the exchange of detainees. https://www.osce.org/chairmanship/391322

And in June, presidents of Ukraine and Russia raised the issue during a telephone conversation. https://www.president.gov.ua/en/news/prezident-ukrayini-proviv-telefonnu-rozmovu-z-prezidentom-ro-48282

http://en.kremlin.ru/events/president/news/57822