U.S. President Donald Trump said on Friday that in two weeks he should know whether progress is possible in his bid to end Russia's invasion of Ukraine and he again raised the prospect of imposing sanctions on Moscow.

Speaking to reporters in the Oval Office, Trump said "I'm not happy" with any aspect of the effort to find peace.

A week ago Trump held talks in Alaska with Russian President Vladimir Putin and has been unable thus far to coax him into a meeting with Ukraine President Volodymyr Zelenskiy. "There's a tremendous amount of hatred there," said Trump. "But we'll see what happens. I think in two weeks, we'll know which way I'm going."

He said he would decide then whether to impose "massive sanctions" or do nothing and say "it's your fight."