Ukraine has largely been driven out of Kurakhove, a battered but strategic town in the Donbas, Russia said. Kyiv’s forces were pressing a renewed offensive in southern Russia.

The surprise attack seeks to reverse Ukraine’s decreasing hold of the region. Since Kyiv’s forces gained partial control of Kursk following a daring cross-border assault last August, Russian troops, aided by North Korean soldiers, have halved the territory held by Ukraine, albeit while suffering thousands of casualties.