French President Emmanuel Macron has warned that a possible US withdrawal from Iran's nuclear deal could lead to a war.

In an interview with Der Spiegel, Macron pointed to US President Donald Trump's threats to abandon the nuclear agreement, known as the Joint Comprehensive Plan of Action (JCPOA), and said, "That would mean opening Pandora's box, it could mean war," The Hill reported on Friday.

"I do not believe that Donald Trump wants war," Macron added.

“My view — I do not know what your president will decide — is that he will get rid of this deal on his own, for domestic reasons,” the French president pointed out.

Such a measure "can work in the short term but it is very insane in the medium to long term,” he added.

Iran and the five permanent members of the United Nations Security Council – the US, France, Britain, Russia and China – plus Germany signed the JCPOA on July 14, 2015, and started implementing it on January 16, 2016.

Under the JCPOA, Iran undertook to put limits on its nuclear program in exchange for the removal of nuclear-related sanctions imposed against it.

Trump has described the deal, which was negotiated under his predecessor, Barack Obama, as “the worst and most one-sided transaction Washington has ever entered into,” a characterization he often used during his presidential campaign, and threatened to tear it up.

The US president has threatened to pull out of the JCPOA unless Congress and America's European allies help “fix” it by May 12.

In late April, Macron made a visit to the US mainly to persuade Washington to stay in the JCPOA. Following the meeting, the French president told reporters that he thought Trump would decide to exit the deal.

Macron noted that a new deal is needed with Tehran which should incorporate three additional elements, namely Iran's ballistic missile program, the country’s regional influence and what happens after 2025 when Tehran will restart part of its nuclear program under the accord.

Iranian leaders, however, have repeatedly stressed that the JCPOA is non-negotiable and dismissed the possibility of continuing with the agreement solely with America's European allies.

Meanwhile, Israeli Prime Minister Benjamin Netanyahu has once again accused Iran of continuing to hide and expand what he called its nuclear weapons program.

On Tuesday, he presented what he alleged was “new and conclusive proof” of violations, and claimed Iran had lied about its capabilities at the time of the agreement’s signing.

A day after Netanyahu’s allegation, the UN nuclear agency reiterated in a statement that it had “no credible indications of activities in Iran relevant to the development of a nuclear explosive device after 2009,” citing its assessments from 2015.

Following Netanyahu’s allegations, EU foreign policy chief Federica Mogherini also said any claims on the Iranian nuclear program should solely be assessed by the IAEA.

British Foreign Secretary Boris Johnson also reaffirmed his country’s support for the landmark nuclear deal, noting that the JCPOA was “based on tough verification.”

Russia and China, as the other signatories to the JCPOA, have warned against efforts to scrap the landmark accord and pledged to continue to honor their commitments under the deal.