Western officials have informed the BBC that North Korean troops have sustained almost 40% casualties during the conflict in Russia's western Kursk region in just three months.
Anonymously speaking, the officials revealed that out of the roughly 11,000 troops dispatched from North Korea, known as DPRK (Democratic People's Republic of Korea), 4,000 have been casualties in battle.
This term encompasses those who have been killed, wounded, are missing, or have been captured. Among the 4,000 casualties, it is estimated that around 1,000 have been killed as of mid-January.
If these losses are confirmed, they are considered unsustainable by North Korean standards.
The whereabouts of the wounded soldiers for treatment remain unclear, as well as the timing and extent of potential replacements.
The significant toll indicates a heavy price being paid by President Vladimir Putin's ally, Kim Jong Un, as he supports efforts to dislodge Ukrainian forces from Russia in anticipation of potential ceasefire talks later in the year.
Amid a lightning incursion by Ukraine into the Russian oblast of Kursk last August, catching Russian border guards off guard, Kyiv clarified its intention not to secure the captured territory permanently but to leverage it in future peace negotiations.
Although Ukraine has gradually lost ground gained in Kursk, partly due to the North Koreans entering Russia in October, they still control several hundred square kilometers of Russian territory and continue to inflict substantial losses on their adversaries.
The North Korean troops, reportedly part of an "elite" unit known as the Storm Corps, seem to have been deployed with limited training and protection.
Former British Army tank commander, Col Hamish de Bretton-Gordon, remarked, "These are barely trained troops led by Russian officers whom they don't comprehend. Frankly, their survival chances are slim. They are being unwittingly sacrificed without much hope of surviving. They are essentially expendable, with Russian officers showing little regard for them compared to their own soldiers."
According to reports attributed to South Korean intelligence, the North Korean forces are ill-prepared for modern warfare realities and are particularly susceptible to being targeted by Ukrainian First-Person-View (FPV) drones, a weapon long familiar in the battle zones of Ukraine's Donbas region.
Despite this, Ukraine's top military commander, Gen Oleksandr Syrskyi, recently cautioned that North Korean soldiers are presenting a significant challenge for Ukrainian troops on the front lines, citing their numbers, motivation, preparation, and reliance on Soviet-era tactics organized in platoons and companies.