Russian President Vladimir Putin has proposed holding “direct talks” with Ukraine on Thursday in Istanbul, as European leaders and the United States attempt to put pressure on Moscow to agree to a 30-day ceasefire in order to bring an end to the three-year conflict.

Major European powers threw their weight behind an unconditional 30-day Ukraine ceasefire on Saturday, with the backing of U.S. President Donald Trump, and threatened President Vladimir Putin with "massive" new sanctions if he did not accept within days.

European leaders from Britain, France, Germany and Poland joined Ukrainian President Volodymyr Zelensky in Kyiv in urging Russian President Vladimir Putin to accept a 30-day ceasefire or face more sanctions.