In the Oval Office, Trump brandished a photograph he said Vladimir Putin sent him after their summit in Alaska and said he would sign it for the Russian leader.

Russian president Vladimir Putin is reportedly willing to freeze current front lines in exchange for Ukrainian territorial concessions and a NATO membership ban.

U.S. President Donald Trump started the week declaring a diplomatic breakthrough in his bid to prod Moscow and Kyiv closer to peace, announcing he had begun arranging for direct talks between Russia's Vladimir Putin and Ukraine's Volodymyr Zelenskyy.

I was just sent a picture by someone who wants to be [at FIFA World Cup events] badly,” Trump said, holding up the glossy image.

Moscow continues to throw cold water on the prospect of Putin-Zelenskyy meeting, and is insisting Russia have a role in security guarantees for Ukraine.

Republican lawmakers have been overwhelmingly complimentary of President Donald Trump meeting with Vladimir Putin and attempting to put the Russian leader in a room with Ukrainian President Volodymyr Zelensky.

Trump's warning came following a Russian missile attack on a US factory in Ukraine, which injured at least 15 workers.