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

Ukraine has launched a new assault into Russia's Kursk region, five months since Kyiv's surprise incursion into the same border area. Russia has been trying to force the Ukrainian troops out of its territory by sending in reinforcements,

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.