Ukrainian President Volodymyr Zelenskyy said more than 3,000 North Korean soldiers have been killed or wounded fighting for Moscow in Russia's western Kursk region.

"Through various sources of information and intelligence, we assess that North Korean troops who have recently engaged in combat with Ukrainian forces have suffered around 1,100 casualties," the JCS said in a statement.

South Korea's military has said that North Korea is preparing to continue aiding Russia in its war with Ukraine, despite casualties.