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.

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