The announcement was made by leaders of Britain, France, Germany, Poland and Ukraine after a meeting in Kyiv, and a phone call with President Trump.

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

The leaders of Germany, France, the United Kingdom and Poland have arrived in Kyiv for key meetings with Ukraine’s President Volodymyr Zelensky, a symbol of a united European position to publicly pressure Russian President Vladimir Putin.