Seoul, April 2 (AHN) North Korean troops have incurred more than 5,000 casualties while fighting Ukrainian forces in Russia's western front-line region of Kursk, Britain's defence ministry has said.

As of last month, approximately a third of the total casualties had been killed in action, according to an intelligence update posted on the ministry's X account Friday.

The casualty figure amounts to nearly half of the initial 11,000 troops North Korea sent to Russia last year in support of its war against Ukraine, Yonhap news agency reported.

"Significant DPRK casualty rates have almost certainly been sustained primarily through large, highly attritional dismounted assaults," the ministry said, using the acronym of the North's official name -- the Democratic People's Republic of Korea.

It noted North Korean and Russian forces have made territorial gains in Kursk in recent weeks, adding the North's operations have been confined to the region and any decision to deploy to Ukrainian territory would require a sign-off from the North's leader Kim Jong-un and Russian President Vladimir Putin.

Last week, South Korea's military said North Korea is estimated to have sustained 4,000 casualties of the 11,000 troops dispatched last year, adding that the North appears to have sent 3,000 more troops to Russia in January and February.

As of April 2025, North Korean forces are believed to have suffered over 5,000 casualties during offensive operations against Ukrainian troops in the Kursk region, according to UK Defense Intelligence. One-third of these casualties were killed in action, with the total losses amounting to nearly half of the 11,000 North Korean troops initially deployed to the area.

Open-source reports suggest that the DPRK has since sent a limited number of additional troops to reinforce its position in Kursk.

The high casualty rates have likely been driven by large-scale, attritional dismounted assaults.

The UK Defence Intelligence assessment raises questions about North Korea’s ability to sustain its military presence in the region under such conditions.