Ukrainian President Volodymyr Zelenskiy said he raised the issue of Russia's compliance with international rules governing the treatment of prisoners of war during a phone call with German Chancellor Olaf Scholz on Wednesday.
He did not elaborate further about the prisoners.
More than 1,000 Ukrainian soldiers who surrendered in the city of Mariupol have been transferred to Russia for investigation, Tass news agency cited a Russian law enforcement source as saying on Tuesday.
Zelenskiy and Scholz also discussed enhancing defence support for Ukraine and global food security, the Ukrainian leader tweeted.
(Reporting by Natalia Zinets; writing by Tom Balmforth; editing by Andrew Heavens)
