President Trump "wants to see a permanent ceasefire first, to stop the killing, stop the bloodshed," press secretary Karoline Leavitt said.

The Kremlin said on Saturday it wanted a definitive response from Ukraine to Russian President Vladimir Putin's offer of a three-day ceasefire next week, criticising the reaction so far as ambiguous and historically wrong.

Russian President Vladimir Putin said there has been no need to use nuclear weapons in the war in Ukraine and expressed hope that such a scenario will not arise.