(Reuters) -Ukrainian President Volodymyr Zelenskiy on Monday congratulated U.S. President Donald Trump on his inauguration and hailed the opportunity to achieve a just peace in his country which has been battling a Russian invasion for almost three years.

Russian President Vladimir Putin said his country was open to dialogue with the new Trump administration on the conflict in Ukraine, as he welcomed what he said was the president-elect's attitude toward preventing a third world war.

Forcing Ukraine to negotiate with Russia before it regains the advantage on the battlefield would be a catastrophic mistake, officials in Kyiv have warned ahead of Donald Trump’s inauguration.

Russian President Vladimir Putin congratulated U.S. President-elect Donald Trump on taking office hours before Trump's inauguration in Washington and said he was open to dialogue with the new U.S. administration on Ukraine and nuclear arms.

President-elect Donald Trump has pledged to broker a peace deal in Ukraine, but as he prepares to take office, peace seems as elusive as ever.

President Vladimir Putin said Russia is open to dialogue with the US on the war in Ukraine as he offered congratulations to incoming President Donald Trump on his inauguration.

Advisers to President-elect Donald Trump now concede that the Ukraine war will take months or even longer to resolve, a sharp reality check on his biggest foreign policy promise - to strike a peace deal on his first day in the White House.

Donald J. Trump’s promise to broker peace between Russia and Ukraine in 24 hours, “before I even become president,” proved to be untrue.