Western diplomatic sources in Moscow told NHK in mid-December that the idea to send North Korean troops to Russia originated in Pyongyang, not Moscow.

Secretive North Korea has one of the world’s largest militaries, with 1.28 million active soldiers, but unlike in Russia, the Korean People's Army (KPA) has no recent experience of combat. Pyongyang’s army is “thoroughly indoctrinated but with low readiness,” says Mark Cancian, from the Centre for Strategic and International Studies (CSIS).

North Korea and Russia are deepening their military cooperation, as Pyongyang ramps up the supply of arms to Moscow for its war in Ukraine and receives much needed cash and oil from the Kremlin in return.

There are risks of North Korea sending additional troops and military equipment to the Russian army,” Zelensky said. “We will have tangible responses to this.”

Despite the relatively high casualty rate, Zelensky added that North Korea might send even more resources to Russian dictator Vladimir Putin’s armies.

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

The Russian army went to war in Ukraine in February 2022 with around 2,000 tracked howitzers. In 34 months of brutal combat, the army has lost no fewer than 800 of these self-propelled artillery pieces to Ukrainian action. Hundreds more have been sidelined by a shortage of fresh gun barrels.

"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.

The Democratic People’s Republic of Korea has, for the first time, sent combatant units abroad, to aid Russia in the war in Ukraine. As noted in the Joint Statement on the DPRK’s Deployment of Troops to Russia this development indelibly connects the Indo-Pacific and European theaters,

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.

South Korea warns of North Korea’s preparations to supply more troops and drones to aid Russia in the Ukraine war.