However the talks aim to remove remaining obstacles in the initiative extended last week and ease global food shortages by unblocking Ukrainian and Russian exports, they added.
Putin said on Wednesday that Russian officials would work to unblock Russian fertilisers stuck in European ports and to resume ammonia exports.
The export of Russian ammonia would be via an existing pipeline to the Black Sea.
Neither Russia nor Ukraine have released official figures on how many prisoners of war they have taken since Russia invaded in February.
On Oct. 29, Ukrainian President Volodymr Zelenskiy said that since March, Russia had freed a total of 1,031 prisoners.