US President-elect Donald Trump has met the French and Ukrainian presidents during his first overseas trip since the November presidential election.

Trump is visiting France to attend a ceremony to mark the reopening of Notre-Dame Cathedral which was damaged by fire five years ago.

Ahead of the ceremony on Saturday, he met French President Emmanuel Macron at the presidential palace in Paris. Macron said that he is happy to again welcome Trump to Paris.

Trump said, "we had a lot of success, very great success working together, working on defense and it really seems that the world is going a little crazy right now and we will talk about that."

Ukrainian President Volodymyr Zelenskyy later joined the talks, the details of which remain unknown. But the three are believed to have discussed prospects for the situation in Ukraine and other issues.

They appeared before reporters after the meeting, shaking hands and talking to each other.

Zelenskyy posted a comment on social media, that said he had a "good and productive trilateral meeting."

He added, "President Trump is, as always, resolute." "We agreed to continue working together and keep in contact. Peace through strength is possible."

During the meeting, Zelenskyy is believed to have stressed the importance of a fair peace for Ukraine, reiterating the position that his country cannot accept a situation in which it will be forced to make unilateral concessions.

The focus is on what Trump had to say at the meeting ahead of his inauguration in January. The president-elect has vowed to bring about a negotiated end to the fighting in Ukraine.