North Korea began sending an estimated 11,000 troops to the Russian Kursk region late last year, soon after North Korean leader Kim Jong-un and Russian President Vladimir Putin agreed on a mutual defense pact designed to strengthen their alliance against what they called a US-led “Western hegemony.”

North Korean troops have not been seen on the frontlines in Russia’s Kursk region for several weeks, a Ukrainian military official said Friday, amid reports of mass casualties among Pyongyang’s forces.

North Korean soldiers previously fighting alongside Russia's army on the Kursk front line appear not to have been engaged in combat since mid-January, South Korea's spy agency told AFP on Tuesday, after Ukraine claimed they had been withdrawn following heavy losses.

A military source, who requested anonymity to discuss sensitive information, described a marked improvement in the precision in all the more than 20 North Korean ballistic missile

North Korean troops, largely special ops forces, have suffered high casualties in bloody assaults not unlike other units, including prison units.

"The worst problem we are facing is the one coming from North Korea," the head of Kyiv's military intelligence agency said in the fall.

It also shed some light on the mindset and training of the conscripted North Korean soldiers sent to fight Russia’s war a continent away from their home. Highly disciplined, ready to die but also very young and with little battlefield experience they elicited curiosity and even some pity from the Ukrainian soldiers who captured them during two separate missions on Jan.