Ukrainian troops are still fending off Russian and North Korean forces in Russia's Kursk region but face a potential new attack on Ukraine's northeast Sumy region, President Volodymyr Zelenskiy said on Saturday.

Russian President Vladimir Putin has called on Ukrainian troops in the Russian region of Kursk to surrender, as diplomatic back-and-forth continues over a potential US-brokered ceasefire with Ukraine.

Russia's Security Council's Deputy Chairman Dmitry Medvedev attends a meeting of the Council for Science and Education at the Joint Institute for Nuclear Research in the Moscow region's city of Dubna,