The Kremlin has accused Ukraine of indefinitely postponing a scheduled exchange of prisoners of war and soldiers' bodies, leaving more than 1,200 sets of Ukrainian remains waiting at an exchange point with no-one to pick them up.

Ukraine has denied the claims, saying Russia acted unilaterally by bringing the remains to the exchange point and no date had actually been agreed to.

The two countries on Monday conducted a second round of peace talks in Istanbul, where they agreed to exchange prisoners, focusing on the youngest and most severely wounded.

They also agreed to arrange for the return of the bodies of 12,000 soldiers who had died in the conflict, with each side handing over 6,000 sets of remains to the other.

Kremlin aide Vladimir Medinsky wrote on Telegram on Saturday that Russia had begun an operation to hand over its more than 6,000 bodies to Ukraine, "in strict accordance with the Istanbul agreements".

He said 1,212 bodies of killed Ukrainian soldiers were ready in refrigerated containers at the exchange point, located on the border between the two countries, on Friday — but Ukrainian negotiators had not shown up.

"We are on site. We are fully prepared to work. International TV channels, news agencies and correspondents are welcome to come and see for themselves that this is indeed the case," he said.

Russia had also handed over to Ukraine its first list of 640 prisoners of war, consisting of "wounded, seriously ill and young people", in order to begin a prisoner exchange, he added, urging Ukraine to stick to the schedule.

However, in response, Ukrainian security official Andriy Kovalenko said Russia's claims were simply untrue.

Mr Kovalenko, an official at Ukraine's National Security and Defence Council, urged Russia to stop "playing dirty mind games" and return to constructive work.

"Today's statements by the Russian side do not correspond to reality or to previous agreements on either the exchange of prisoners or the repatriation of bodies," he said on Telegram.

He said an agreement on the repatriation of bodies had indeed been reached at Monday's talks, but no date had yet been agreed to.

Russia had instead "resorted to unilateral actions", he said.

A statement released by Ukraine's state-run Coordination Headquarters for the Treatment of Prisoners of War said Ukraine had also handed over a list of 640 prisoners of war that would be released in the first swap.

However, it said Russia's list did not correspond to the agreed approach as to which prisoners would be prioritised in the exchange.

Still no ceasefire agreement

Representatives from Ukraine and Russia met for around an hour on Monday in Istanbul, for only the second such round of negotiations since March 2022.

Turkish President Recep Tayyip Erdoğan described the meeting as "great" and said he hoped the next meeting would include Russian President Vladimir Putin, Ukrainian President Volodymyr Zelenskyy and US President Donald Trump.

Both sides agreed to exchange more prisoners of war and return the bodies of 12,000 dead soldiers.

However there was no breakthrough on a proposed ceasefire that Ukraine, its European allies and Washington have all urged Russia to accept.

The Kremlin said the process of reaching a settlement that would end the war in Ukraine was extraordinarily complex, and it would be wrong to expect any imminent decisions.

Kyiv said Mr Putin is not interested in peace, but proposed holding more talks before the end of June.

Mr Zelenskyy has also a proposed ceasefire until a meeting can be arranged with the Russian president.

"My proposal, which I believe our partners can support, is that we agree a ceasefire with the Russians until the leaders meet," Mr Zelenskyy said.

"At this time, people will understand that the nations, Europe, Ukraine and the whole world have a chance to end the war."

Reuters

Source: Australian Broadcasting Corporation.