Moscow announced it had returned the bodies of more than 1,200 Ukrainian soldiers, and in turn received the remains of 27 Russian soldiers.

Ukraine and Russia exchanged another group of ill and severely wounded servicemen on Thursday, officials from both countries said. All of the Ukrainian troops need treatment, Ukraine's President Volodymyr Zelenskiy said in a message on the Telegram messaging app that did not go into details on the numbers involved.

Since then, Russia and Ukraine have swapped dozens of prisoners of war, focusing on under-25s and the severely wounded and sick.