President Donald Trump announced he has canceled a planned meeting with Vladimir Putin at a G-20 summit in Argentina amid tensions over Russian-seized Ukrainian ships and new revelations about 2016 campaign contacts with Moscow.

Trump first told reporters Thursday morning on the South Lawn of the White House that he and his staff had not “terminated” the one-on-one meeting. But less than an hour later, as Air Force One was in the first hour of a long flight to the South American country, he reversed his statement.

“Based on the fact that the ships and sailors have not been returned to Ukraine from Russia, I have decided it would be best for all parties concerned to cancel my previously scheduled meeting……..in Argentina with President Vladimir Putin. I look forward to a meaningful Summit again as soon as this situation is resolved!” Trump wrote in a pair of tweets.

The Kremlin had announced earlier Thursday the meeting would occur.

Trump nixed his second face-to-face private session with Putin after his former “fixer” and attorney Michael Cohen pleaded guilty to lying to Congress about his work on a proposal to build a Trump Tower in Moscow.

Court documents filed by special counsel Robert S. Mueller III show Cohen tried to get the help of Putin on Trump’s behalf as they sought a way to get the building project going. They also show Cohen and others in Trump’s circle had many more contacts with Russians than previously acknowledged by the Trump team.

Trump told reporters as he left the White House he would be reading a “final report” about Russia’s actions against those Ukrainian ships as he flew to Argentina.