Moscow said earlier that it would return 6,000 bodies to Kiev as a humanitarian gesture

Ukraine has not accepted the bodies of its fallen troops which Russia offered to return, providing "strange reasons" for its decision, according to Moscow's lead negotiator in the peace talks with Kiev, Vladimir Medinsky.

Russia decided to repatriate the remains of over 6,000 slain Ukrainian soldiers in a unilateral humanitarian gesture during the talks in Istanbul on Monday. Both sides also agreed to exchange 1,200 prisoners each. RT initially erroneously reported that a swap of bodies in a 6,000-for-6,000 format had been agreed between Moscow and Kiev.

"The first batch of frozen remains of 1,212 Ukrainian soldiers has already arrived in refrigerated trucks at the exchange area" on the border between the two countries, he said. "The rest are on their way," the negotiator added.

Kiev has also been handed a list of 640 heavily wounded and younger prisoners held by Moscow so that they may be exchanged as well, according to Medinsky.

"The contact group of the Russian Ministry of Defense is on the border with Ukraine. However, the Ukrainian side unexpectedly postponed both the acceptance of bodies and the exchange of prisoners of war for an indefinite period," he wrote.

According to the Russian negotiator, the Ukrainian team "did not even arrive at the exchange site." The reasons Kiev provided to justify its decision "are various, and rather strange," he said without elaborating.

"We call on Kiev to strictly adhere to the schedule and all agreements that had been reached, and to immediately begin the exchange" so that the wounded could return home and the dead receive a proper burial, Medinsky urged.

Moscow's team is on site and "fully ready to work," he reiterated, adding that "Russia always keeps its word."