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

European leaders have called US President Donald Trump to discuss proposals for a 30-day ceasefire between Russia and Ukraine from Monday while on a visit to Kyiv. The call came after leaders of the so-called "coalition of the willing" held a meeting to discuss advancing peace talks.

It’s a proposal that the Kremlin can neither reject nor accept, but one that may force it into an awkward choice, revealing Russian President Vladimir Putin’s true appetite for his brutal war of choice.