A new prisoner swap between Ukraine and Russia has begun, officials in both countries said Monday, with Ukrainian soldiers who have spent nearly the entire duration of the war in captivity among those returning home.

Russia and Ukraine started a major prisoner exchange on Monday after days of wrangling cast doubt over the only concrete result of peace talks last week in Turkey.

It restated Moscow's demands that Ukraine become a neutral country - ruling out membership of NATO - and that it protect the rights of Russian speakers, make Russian an official language and enact a legal ban on glorification of Nazism. Ukraine rejects the Nazi charge as absurd and denies discriminating against Russian speakers.

Since last sitting down with Ukraine to talk peace, Russia has launched four of its five largest drone attacks against the country, killed more than 340 of its civilians and continued to peddle its false narrative about the unprovoked war it has been waging for more than a decade.