Emmanuel Macron says he expects Donald Trump to pull out of the international deal designed to prevent Iran acquiring nuclear weapons.

A Question and Answer session with students at George Washington University wrapped up the French president's three day visit and he voiced his doubts over Iran at a final press conference before returning to France.

"I don't know what the American decision will be, " he said. "But the rational analysis of all President Trump's statements doesn't lead me to believe that he will do everything to stay in the JCPOA".

After what had been called a "bromance" between the two Presidents during the first two days of the visit, Macron's address to the joint houses of Congress was highly critical of Trump's position on climate change and international trade.