British Prime Minister Keir Starmer has become the first European leader to say he is ready to put peacekeeping troops in Ukraine, making the commitment ahead of an emergency leaders' meeting in Paris to discuss Europe's role in a ceasefire.

Starmer's comments underlined a growing realization among European nations that they will likely have to play a larger role in ensuring Ukraine's security as Washington works alone with Russia on a potential end to the three-year conflict.

Sweden would consider contributing to post-war peacekeeping forces in Ukraine, Prime Minister Ulf Kristersson said on Monday, adding that negotiations would need to progress before any such decision was taken.

U.S. President Donald Trump stunned Ukraine and European allies last week when he announced he had held a call with Russian President Vladimir Putin, without consulting them, to discuss bringing an end to war.