KRAMATORSK, Ukraine (BLOOMBERG) - Ukraine and two breakaway regions supported by the Kremlin exchanged prisoners on Sunday (Dec 29) under an agreement reached with Russian President Vladimir Putin earlier this month as the former allies seek an end to more than five years of war in the Donbas area.

Ukraine received 76 captives from the Russian-backed rebels, President Volodymyr Zelenskiy's office said on Sunday when announcing the completion of the swap.

Ukraine returned 127 captives to the self-proclaimed Donetsk and Luhansk republics, Ukrainian Hromadske TV reported, citing Serhiy Sivokho, adviser to the head of the National Security and Defence Council.

Zelenskiy and Putin met the leaders of France and Germany in the first week of December in an effort to resume the peace process, which has become a main point of division between Russia and the West.

The US and European Union accuse the Kremlin of stoking the conflict and responded with economic sanctions that are still in place.

Putin and German Chancellor Angela Merkel "gave a positive assessment" of the swap, the Kremlin said on Sunday after the leaders spoke by phone.

Ukraine's Foreign Minister Vadym Prystaiko said on his Twitter feed that the "all for all" formula for exchanging verified prisoners will be discussed as a priority at the next Normandy format meeting with Germany, France and Russia.

The deadly conflict in Ukraine's east erupted soon after Russia's annexation of Crimea in 2014.

Fighting between Ukrainian forces and Russian-backed separatists has claimed more than 13,000 lives since it began, and negotiators have struggled to make a ceasefire stick along the 500km contact line.

In September, Ukraine and Russia exchanged 35 prisoners each. The Ukrainians who were freed included a filmmaker and 24 sailors while the authorities in Kyiv handed over militants captured during the fighting in Donbas.