Russia and Ukraine agreed to a new prisoner exchange after their delegates met for a second round of renewed peace talks in Istanbul on Monday, but there was no sign the warring sides were any closer to reaching a ceasefire deal than they were when direct negotiations were restarted a month ago.

Russia and Ukraine began a major prisoner exchange, swapping hundreds of soldiers and civilians in the first phase of an exchange that was a moment of cooperation in otherwise failed efforts to reach a ceasefire in the 3-year-old war.

Russia and Ukraine began their largest exchange of prisoners of war on Friday, with each side returning 390 soldiers and civilians, according to both governments. More swaps were expected on Saturday and Sunday, as the two countries have committed to exchange 1,000 prisoners each.