French President says his country will not leave the Iran nuclear deal, known as the Joint Comprehensive Plan of Action (JCPOA), amid US efforts to persuade European parties to the agreement to withdraw from it.

Speaking at the US Congress on the final day of a three-day state visit, Emmanuel Macron said the JCPOA was not addressing what he called “all concerns” but stressed that the deal could not be ditched.

"We signed it, both the United States and France."

"We should not abandon it without having something substantial and more substantial instead. That's why France will not leave the JCPOA, because we signed it," he said.

He also vowed that Iran will "never" be allowed to develop atomic weapons.

"Our objective is clear. Iran shall never possess any nuclear weapons. Not now. Not in five years. Not in 10 years. Never," Macron said.

Earlier on Tuesday, the French president said after the meeting with his US counterpart Donald Trump that Paris wants to work on a new nuclear deal with Iran.

Trump has often vowed to pull the United States out of the 2015 nuclear pact between Iran and the P5+1 group of countries, which was negotiated under his predecessor, Barack Obama.

Back in January, Trump said it was the last time he was extending the sanctions relief for Iran as part of the nuclear agreement, giving the European signatories a May 12 deadline to fix what he claimed to be the “flaws” in the agreement or he would refuse to waive those bans.

Iran has repeatedly warned that any failure to respect the multinational agreement would have grave consequences, stressing that there is no alternative to the nuclear accord.

US President Donald Trump has consistently been criticizing the 2015 deal, which was inked by Iran, the European Union and the P5+1 group (the United States, Russia, China, France, and the United Kingdom plus Germany).