French President Emmanuel Macron said he thinks US President Donald Trump will withdraw from the Iran nuclear accord, dealing a blow to the agreement reached in 2015 and endorsed by world powers.

"I believe he will get rid of this deal for domestic reasons,” Mr Macron told journalists on Wednesday in Washington, adding that he encouraged the US president to stay in the accord during his three-day visit to Washington.

Mr Macron went on to say that a US withdrawal, which isn’t backed by any of the other five countries who are part of the agreement, would lead to a period of increased tensions and uncertainty over Iranian and US reactions.

The comments come a day after Mr Macron and Mr Trump hosted a news conference in which the French president proposed a new agreement which would try to address many of Mr Trump’s concerns about the six-party accord, which he has called “insane” and the “worst deal ever.”

Keeping the US in the agreement reached during the Obama administration has been a priority issue for Mr Macron and European leaders ahead of a May 12 deadline for Mr Trump to continue to waive US sanctions that were lifted as part of the deal.