For months now, thousands of North Korean soldiers have been storming trenches, dodging artillery fire, fighting alongside Russian troops trying to dislodge Ukrainian forces from Russian territory.
When they first appeared last fall, the North Korean deployment worried Western officials, who feared they would pummel Ukrainian troops, already-beleaguered elsewhere the 1,100-kilometer front line, and force a retreat.
That didn't happen. And now, North Korean troops are reportedly being pulled back from the front lines. The reason, according to a New York Times report on January 31, appears to be high casualties.
Ukraine authorities had mixed assessments of the Times report: One military intelligence official, who spoke on condition of anonymity, told Current Time that North Korean troops indeed had been rotated out, due to “big losses” but characterized their movement as “standard operations.”
Ukraine’s special operation command, however, told RFE/RL’s Ukrainian Service that North Korean troops had not been observed in areas where special forces were fighting for approximately three weeks: “Likely having suffered significant losses, they were forced to retreat."
If a North Korean withdrawal, or even a major retreat, is confirmed, it would be a potentially embarrassing setback for Russian commanders -- not to mention a blow to the notion that the North Korean troops would be able to make a decisive battlefield difference.
Here’s what we know so far.
From Pyongyang To Kursk
After weeks of Ukrainian warnings, bolstered by satellite images and other open-source intelligence, North Korean troops started appearing in Russian regions bordering Ukraine in mid-October. More than 11,000 in all, officials said at the time.
At the time, it wasn’t fully clear why Russian officials had turned to Pyongyang for help; some experts suggested President Vladimir Putin was trying to avoid calling a new mobilization, or sending conscripts into battle -- something that would spark opposition inside Russia.
Western officials portrayed it as a sign of desperation. Western estimates put Russia’s casualties since the start of the all-out invasion in February 2022 at more than 700,000 killed or wounded.
“This is an indication that he may be in even more trouble than most people realize,” then-U.S. Defense Secretary Lloyd Austin said in October, referring to Putin. “He went tin-cupping early on to get additional weapons and materials from” North Korea.
Ukrainian officials predicted they would end up in Kursk, a border region where Ukraine had surprised Russia with an invasion two months prior.
Indeed, Ukrainian units reported multiple encounters with North Koreans and have even taken some prisoners.
Have They Made A Difference On The Battlefield?
When Ukraine punched across the border in August 2024, its forces -- some of which included Kyiv’s most experienced, battle-hardened units -- quickly seized a sizable amount of territory in Kursk: about 1,300 square kilometers at its maximum.
It was the biggest invasion of Russian territory by a foreign military since World War II.
Russia’s defense was initially shambolic, and disorganized-- which prompted surprise and outrage, particularly among local residents. But commanders redeployed units, slowly pushing Ukrainian troops back. North Korean soldiers deployed in October; Ukrainian officials reported first clashes with them in early November.
Russia and North Korea’s combined forces to date have retaken a little more than half the territory Ukrainian forces had seized in Kursk.
Days after the New Year, Ukrainian commanders ordered a new offensive in the Kursk region, to roll back North Korean gains.
The reasoning again was unclear, though some experts said it might have been to gain territory and jockey for position ahead of possible peace negotiations that U.S. President Donald Trump is pushing for.
It was during that effort that Ukrainian troops appeared to have captured several North Koreans.
"They operate according to Soviet tactics, they operate in platoons, companies. They take advantage of their mass presence,” Ukraine's top military officer, General Oleksandr Syrskiy, said in an interview last month. "They are quite brave; of course, this is a problem.”
So How Bad Are North Korean Casualties?
Ukrainian officials claim to have inflicted substantial casualties on North Korean troops; President Volodymyr Zelenskiy put the number at more than 3,000 in late December.
Military intelligence has released images of items captured from North Korea troops -- books, pamphlets, even cell phones -- though little of their contents has been shared publicly.
In his interview, Syrskiy estimated about half of the 11,000-12,000 deployed troops had been killed or wounded.
But Ukrainian estimates have been impossible to verify.
Days before Zelenskiy gave his estimate, South Korea’s main intelligence service said around 1,100 North Koreans had been killed or wounded. The White House gave a comparable estimate on December 27: “more than 1,000 killed or wounded in this particular fighting in just the past week.”
South Korean intelligence gave an updated tally on January 13: 200 North Koreans killed; 2,700 wounded.
Pulling North Korean troops back from front-line fighting could be a sign of how effective Ukrainian attacks have been, particularly if they’re prioritizing targeting Pyongyang's soldiers.
But troop rotations are also normal in any battlefield: Exhausted soldiers need rest; units with high casualties need to be replenished or reorganized; ammunition and shells need to be stockpiled.
