Russia and Ukraine have agreed on a large-scale prisoner exchange. The Guardian. Russia's chief negotiator at the peace talks in Abu Dhabi, Vladimir Medinsky, said after their conclusion that a mutual understanding had been reached on several issues and that further negotiations would take place. Medinsky said Russia and Ukraine had agreed to a large-scale prisoner exchange, the latest in a long line of similar deals. However, he is wary of the possibility of European countries joining the negotiations and said that it is not clear what exactly Russia and the European Union will discuss, given, according to him, the lack of proposals from the European side, Reuters reports.