The two leaders held talks ahead of attending the service in Vatican City on Saturday.

Trump had previously warned both sides his administration would walk away from its efforts to achieve a peace if the two sides do not agree a deal soon. The meeting in Rome is the first face-to-face encounter between Trump and Zelenskiy since an Oval Office meeting in February that turned into a shouting match.

U.S. President Donald Trump and Ukrainian leader Volodymyr Zelenskiy had a "very productive" meeting on Saturday in Rome, a White House official said, as both leaders attended the funeral of Pope Francis.