This file photo shows Russian troops in the devastated port city of Mariupol. AFP
The Ukrainian campaign took Russian troops by surprise and resulted in Kyiv seizing more than 1,000 square kilometres (400 square miles) of territory.
"During offensive operations, units of the Northern Group of Troops liberated the village of Oleshnya," the Russian defence ministry said on Telegram.
Now only one other village, Gornal, remains under Ukrainian control.
Russian soldiers recaptured large swathes of the region in March, notably driving the Ukrainians out of the small town of Sudja, their main base of operations in the area.
Russian troops are now at the border and are poised to beef up threats to the Ukrainian region of Sumy, which faces Kursk, where they have already carried out incursions in recent weeks.
On Saturday, a Ukrainian drone strike on a car in the Kursk region killed a woman and injured a man and a child, regional governor Alexander Khinstein said on Telegram.
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