The leaders of Britain, France, Germany and Poland met Ukrainian President Volodymyr Zelenskiy for talks in Kyiv on Saturday in a show of unity a day after Russia's Vladimir Putin hosted his allies at a Victory Day parade in Red Square.

Ukraine’s Western allies said they would strengthen sanctions if Russia refused an unconditional 30-day ceasefire.

Ukraine and European leaders agreed on Saturday to an unconditional 30-day ceasefire from May 12 with the backing of U.S. President Donald Trump, threatening President Vladimir Putin with new "massive" sanctions if he failed to comply.