Ukrainian forces have pulled almost entirely out of the Kursk region of Russia, ending an offensive that had stunned the Kremlin last 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 their 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.

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