Ukrainian forces have pulled almost entirely out of the Kursk region of Russia, ending an offensive that had stunned the Kremlin over the summer with its speed and audacity.

Ukrainian soldiers at the front described a retreat that was organized in places and chaotic in others, as Russian forces stormed through their lines and forced them back to a sliver of land along the border.

By the time one Ukrainian assault platoon retreated from its position less than a week ago, all the soldiers’ vehicles had been destroyed, drones hunted them night and day, and they were almost out of ammunition.

Russian forces were closing in from all directions, said the platoon’s commander, “prompting our retreat.”

The commander, who asked to be identified only by his call sign, Boroda, in keeping with military protocol, said it took his unit two days to hike more than 12 miles from their positions near the Russian village of Kazachya Loknya to the Ukrainian border. By then, “the area where our positions had been was already occupied by Russian forces,” he said when reached by phone.At the height of the offensive, Ukrainian forces controlled some 500 square miles of Russian territory. By Sunday, they were clinging to barely 30 square miles along the Russia-Ukraine border, according to Pasi Paroinen, a military analyst with the Finland-based Black Bird Group.

“The end of the battle is coming,” Paroinen said in a phone interview.

How much Russian territory Ukraine still controls in Kursk could not be independently confirmed, and soldiers reported fierce fighting was ongoing. But the fighting near the border is now less about holding Russian land, Ukrainian soldiers said, and more about trying to prevent Russian forces from pouring into the Sumy region of Ukraine and opening a new front in the war.

The soldiers said they are trying to set up strong defensive positions along ridgelines on the Russian side of the border.

“We continue to hold positions on the Kursk front,” Boroda said. “The only difference is that our positions have shifted significantly closer to the border.”

Andrii, a Ukrainian intelligence officer fighting in Kursk, put it more bluntly: “The Kursk operation is essentially over,” he said. “Now we need to stabilize the situation.”

While Ukrainian forces have managed to stall Russia’s advance in eastern Ukraine, the turn in Kursk comes as the Trump administration is pushing for a quick truce.

The reversal of Ukraine’s fortunes in Kursk did not come down to any one factor. Russian forces pounded Ukraine’s supply lines and began to cut off escape routes. North Korean troops brought in by Moscow, who faltered at first, improved their combat capabilities. And at a crucial moment, U.S. support — including intelligence sharing — was put on hold.

How the tide turned

When The New York Times last visited the border between Sumy and Kursk in late January, daytime movement was nearly impossible because the skies were filled with Russian drones.

The main road from Sumy to Sudzha, a small Russian town about 6 miles to the northeast that Ukrainian forces had occupied since August, was already littered with burned-out cars, tanks and armored vehicles.

Ukraine had dispatched some of its most experienced brigades to the Kursk operation, but months of unrelenting assaults by Russian forces and the thousands of North Korean troops fighting alongside them were taking a growing toll.

By mid-February, Russian forces had advanced to within 5 miles of Ukraine’s main resupply routes into Sudzha, allowing them to target the roads with swarms of drones — many of which were tethered to ultrathin fiber optic cables and therefore immune to jamming.

Other Ukrainian soldiers, who like Boroda asked to be identified only by their first name or call sign in accordance with military protocol, described Russian forces using attack drones for ambushes.

“Their drones would land near key supply routes and wait for a target to pass by,” said Cap, a 36-year-old Special Operations Forces fighter who asked to be identified by his call sign.

Russian drones were also hitting pre-placed explosives to destroy bridges in Kursk, to try to make it harder for Ukrainian troops to retreat, Ukrainian soldiers said.

Russian warplanes also attacked bridges, in one case dropping a 6,000-pound guided bomb to cut off one major artery, according to Ukrainian soldiers and military analysts.

Artem, a senior Ukrainian brigade commander, said that the destruction of the bridges was one of the key reasons Ukraine’s forces had to abandon positions so suddenly in recent weeks. Not everyone made it out, but most did, he said.

Russia’s breakthrough

Ukraine’s hold in Kursk was already in danger when the Trump administration announced the suspension of military aid and intelligence sharing March 3.

The sudden loss of U.S. intelligence for precise targeting compounded the difficulties, according to Andrii.

Then, on March 8, Russian troops made a breakthrough, sneaking behind Ukrainian lines by walking for miles through a disused gas pipeline to stage a surprise attack. Russian propagandists and officials cast the operation as a heroic feat, while Ukrainian sources called it a risky move that they claimed had led to many deaths caused by residual methane in the pipeline.

Around the same time, North Korean troops were helping lead an assault that broke through Ukrainian lines south of the small village of Kurylivka, further constraining Ukraine’s ability to supply its troops.

As Ukrainian forces there retreated along designated defensive lines, Russian forces kept pushing toward Sudzha, and the pace of attacks increased.

On March 10, the order was issued for some units to withdraw from Sudzha, three Ukrainian soldiers and commanders said.

“It was a mix of organized and chaotic retreat,” Boroda said. “Various factors influenced the nature of the withdrawal: fatigue, good or poor orders from individual commanders, miscommunication or well-established coordination.”

However, despite claims to the contrary made by Russian President Vladimir Putin and U.S. President Donald Trump, at no point were large numbers of Ukraine’s forces surrounded, according to military analysts who use geolocated combat footage to map battlefield developments, Ukrainian soldiers fighting in Kursk and even some prominent Russian military bloggers.

Three days later, Russia’s Defense Ministry said it had regained full control of Sudzha. On Saturday, it claimed its forces had retaken two villages outside the town.

While the Ukrainian military’s general staff has not directly addressed Russia’s capture of Sudzha, on Sunday it released a map of the battlefield showing the town outside the territory it controls in Kursk — which has shrunk to a narrow strip of land.

Sudzha, once home to 5,000 people, sustained heavy damage in the fighting. And since the Kursk operation began, military analysts say, both sides suffered heavy losses.

While Ukraine had hoped to use its control over Russian land as leverage in any negotiation to end the war, Putin now appears to be using the Ukrainian retreat to try and strengthen his hand in talks with the Trump administration about pausing the hostilities.

Trump and Putin are expected to speak this week, White House special envoy Steve Witkoff said Sunday on CNN’s “State of the Union.”