South Korea's spy agency says an estimated 4,700 North Korean soldiers have been killed or wounded while fighting alongside Russia against Ukrainian forces.

After Russia claimed to have retaken the Kursk region from Ukraine, North Korea acknowledged for the first time that it had sent soldiers to fight in Moscow’s war.

Russia’s President Vladimir Putin has for the first time acknowledged that North Korean soldiers took part in the fighting to recover Russian territory after Ukraine’s incursion into the Kursk region last year.