Russia has claimed that its forces captured a battered but strategic town in Ukraine’s eastern Donetsk region, a day after Kyiv launched a counterattack in the Russian region of Kursk.

Russia said on Monday its forces had made important gains in eastern Ukraine while continuing to fend off a new Ukrainian offensive inside the Kursk region of western Russia, where a second day of fierce fighting was under way.

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.

Ukraine said Tuesday its forces struck a Russian military "command post" in Russia's Kursk region during "combat operations," while backtracking on a claim it had launched a fresh offensive in the border area.

It comes as Ukraine's president says only the US can provide security guarantees leading to an end to the war.

Russian forces continue to make costly but consistent gains in the Donetsk region in eastern Ukraine. They are steadily grinding down a pocket of resistance around the town of Kurakhove and are also fighting to envelop the larger nearby city of Pokrovsk, Ukrainian soldiers and officials said.

Russian forces have seized control of Kurakhove, a town in Ukraine's Donetsk region, the Russian Defence Ministry said on Monday.