US, South Korean and Ukraine intelligence officials said North Korea last year dispatched up to 12,000 troops to Russia.

But North Korea had not confirmed or denied its reported troop deployments to Russia until Monday.

In a statement provided to North Korea’s state media, the North’s Central Military Commission of the ruling Workers’ Party said leader Kim Jong Un had decided to send combat troops to Russia under a mutual defence treaty.

It cited Kim as saying that the troops’ deployment was meant to “annihilate and wipe out the Ukrainian neo-Nazi occupiers and liberate the Kursk area in cooperation with the Russian armed forces.”

“They who fought for justice are all heroes and representatives of the honour of the motherland,” Kim said, according to the statement.

In February, South Korea’s spy agency said North Korea appeared to have sent additional troops to Russia, after its soldiers deployed on the Russian-Ukraine fronts suffered heavy casualties.

In January, the NIS said about 300 North Korean soldiers had died and another 2700 had been injured. Zelenskyy earlier put the number of killed or wounded North Koreans at 4000, though US estimates were lower at about 1200.

Earlier this year, Kim expressed his unwavering support for Russia’s war in Ukraine during a meeting with a top Russian security official, Sergei Shoigu, in Pyongyang.

State media reports said Kim and Shoigu reaffirmed their commitment to uphold the mutual defence treaty agreed upon last year. Russian Deputy Foreign Minister Andrei Rudenko told Russian media the governments were discussing a potential visit by Kim to Moscow.

North Korea has been supplying a vast amount of conventional weapons to Russia as well. South Korea, the US and their partners worry that Russia could reward North Korea by transferring high-tech weapons technologies that can sharply enhance its nuclear weapons program. North Korea is expected to receive economic and other assistance from Russia as well.

North Korean soldiers are highly disciplined and well trained, but observers say they’ve become easy targets for drone and artillery attacks on Russian-Ukraine battlefields due to their lack of combat experience and unfamiliarity with the terrain.

Still, Ukrainian military and intelligence officials have assessed that the North Koreans are gaining crucial battlefield experience and have been key to Russia’s strategy of overwhelming Ukraine by throwing large numbers of soldiers into the battle for Kursk.