Russia's claims that Ukraine is delaying exchange of soldiers' bodies are untrue, Ukrainian officials said on Saturday, urging Moscow to stop "playing dirty games" and return to constructive work. Kremlin aide Vladimir Medinsky said on Saturday that Ukraine had unexpectedly postponed exchanging prisoners of war and accepting the bodies of killed soldiers for an indefinite period.

A large-scale prisoner exchange between Russia and Ukraine -- the only concrete outcome of peace talks -- was thrown into doubt Saturday after Moscow and Kyiv accused each other of delaying and thwarting the swap.