Russian and North Korean forces have made significant battlefield advances in recent days in the Kursk region of Russia, threatening Ukraine’s supply lines and its hold on a patch of land it hopes to use as a bargaining chip in future negotiations, according to Ukrainian soldiers, Russian military bloggers and military analysts.
Working together, a new influx of North Korean soldiers and well-trained Russian drone units, advancing under the cover of ferocious artillery fire and aerial bombardment, have been able to overwhelm important Ukrainian positions, Ukrainian soldiers said.
"It’s true; we can’t stop them,” said Oleksii, commander of a Ukrainian communications unit fighting in the area, when reached by phone. "They just sweep us away, advancing in groups of 50 North Koreans while we have only six men on our positions.
"Decisions are being made here, but I don’t know how effective they will be,” he said.
If Ukrainian forces were cut off or forced to retreat, it would be a significant setback. Not only was the incursion into Kursk a signature operation that boosted morale and embarrassed Russian President Vladimir Putin, but also holding territory in Russia gave Ukraine a potential bargaining chip in any peace negotiations. Pulling out could weaken its bargaining position at a moment when U.S. President Donald Trump is trying to force through settlement talks.
On Friday morning, Trump, who has favored the Kremlin’s position in his public comments, turned the tables on Russia, saying he might impose new sanctions on that country if it kept bombarding Ukraine and did not engage in serious peace talks.
"Based on the fact that Russia is absolutely ‘pounding’ Ukraine on the battlefield right now,” Trump wrote on Truth Social, "I am strongly considering large scale Banking Sanctions, Sanctions, and Tariffs on Russia until a Cease Fire and FINAL SETTLEMENT AGREEMENT ON PEACE IS REACHED. To Russia and Ukraine, get to the table right now, before it is too late.”
Ukrainian forces first swept across the border over the summer in an unexpected assault, overrunning unprepared Russian positions and securing a bridgehead of some 520 square kilometers (200 square miles) around the Russian town of Sudzha, which sits about 10 km (6 miles) from the border.
It was the first time that a foreign army had crossed into Russian territory since World War II.
Military analysts remain divided on whether the surprise decision to carry out an offensive into Russian territory served a useful purpose or was a strategic mistake.
Russian and North Korean soldiers have retaken about two-thirds of the land lost in the summer — but at a horrendous cost, with at least 4,000 troops killed in combat, according to Ukrainian, South Korean and Western intelligence estimates.
Ukrainian officials have said the offensive served multiple goals: thwarting a looming Russian offensive into the Sumy region of Ukraine, demonstrating that Western fears of escalation were overwrought, forcing Russia to divert resources away from the front line in Ukraine and possibly serving as leverage in future peace negotiations.
The recent setbacks in Kursk have come as Ukrainian forces in eastern Ukraine have managed to stall Russian offensive efforts for months and largely stabilize their lines.
Three years into Russia’s full-scale invasion of Ukraine, Putin, who keeps tight control over all information in Russia, has paid no apparent political price for the military embarrassment in Kursk, even as the Kremlin has lost thousands of soldiers in grueling battles to drive the Ukrainians out.
As the battles dragged on, the Russians brought in an estimated 12,000 North Koreans to join the fight. North Korea was already supplying Russia with millions of artillery shells Moscow desperately needed, as well as artillery and ballistic missiles.
For months, Russian and North Korean forces have been attacking in some of the most ferocious clashes of the war, the intensity rising and falling but never really subsiding, soldiers said.
The North Koreans were forced to withdraw from the battlefield in January and regroup, but they soon returned.
Ukrainian President Volodymyr Zelenskyy said Feb. 8 that "Russia has once again deployed North Korean soldiers alongside its troops.” Four Ukrainian soldiers all said in interviews that North Koreans were at the vanguard of the latest waves of attacks, along with elite Russian drone units.
Ukrainian soldiers said the North Koreans were now better adapted to waging war on a battlefield that has been transformed by the proliferation of drones. They still engage in the same ferocious frontal assaults that led to so many casualties, but they are operating more cohesively.
"The North Koreans’ application of tactics is constantly improving,” said Andrii, a drone commander fighting in Kursk. They are working in better coordination with North Korean artillery units and supported by Russian drone operators, he said.
They have helped the Russians break through Ukrainian lines in the western part of the Ukrainian-held pocket near the border, south of Sudzha, according to DeepState, a group of analysts mapping the battlefield based on sources in the Ukrainian military and open-source data like satellite imagery, photos and video posted on social media.
Ukrainian soldiers in the fighting said their lines were broken south of the small village of Kurylivka, where the enemy troops were able to cross a narrow river in January. They quietly amassed forces, soldiers said, but by early March, there were simply too many North Koreans, and when they attacked they overran the Ukrainian positions.
Ukrainian forces retreated in an organized manner along designated defensive lines, Ukrainian soldiers said. The enemy advance has been halted, for the moment.
In addition to having an overwhelming edge in troops and firepower, the Russians have saturated the battlefield with fiber-optic drones. Unlike radio-controlled drones, these are immune to jamming because they are controlled by ultrathin fiber-optic cables that unspool as their pilots guide them to their targets.
Capt. Oleksandr Shyrshyn, a battalion commander in the 47th Mechanized Brigade fighting in Kursk, said that the Russians appeared to have increased the range the drones can fly while bringing some of their best operators to the Kursk region.
Small Russian assault units of just a couple of soldiers are also now sometimes moving forward with the drones, further extending the range pilots can fly them.
"Once they storm in, at approximately 200 to 300 meters from the front line, they start using them from there,” he said.
This, he said, has allowed the Russians and North Koreans to strike more effectively at Ukraine’s main supply line: the only road leading from Ukraine to Sudzha.
That route has long been a target of Russian attacks. On a visit to the border this winter, it was littered with the wreckage of blasted-out armored tanks and other military vehicles that had failed to safely run the gauntlet.
The Russians can now keep that road under near-constant fire.
Shyrshyn said that his soldiers were still able to hold their positions even under increasing pressure, but other soldiers said the situation was growing more difficult by the day.
Andrii, the drone commander, said: "The enemy has strongly focused on cutting our logistics, which affects our ability to hold the defense.
"This was influenced by the number of their drones and the training of their crews,” he said. "It feels like they have gathered their best crews here, and, accordingly, their numbers are large.
"We have losses,” he added, "but we are still carrying out the tasks assigned to us.”
This article originally appeared in The New York Times © 2025 The New York Times Company
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