France's President Emmanuel Macron declared on Wednesday that the Iran nuclear deal is no longer a sufficient safeguard against the growing power that Tehran wields in its region.

“We need the 2015 accord,” he said of the agreement.

He added: “Is this accord enough? It is not, given the growing pressure that Iran is applying in the region.”

Macron was speaking in New York on the sidelines of the United Nations (UN) General Assembly, while ministers from Iran and the six world powers that had signed the accord met to discuss it.

United States (US) President Donald Trump, who was elected after the deal was signed, has threatened to pull out if Iran does not face greater controls on its missile and nuclear programmes.

The other deal signatories, including France, insist it remains the best way to prevent Tehran from developing a nuclear bomb — but Macron has said it could be improved.

He told reporters that Iran's ballistic missile programme must be curtailed and cited the need to reassure “states in the region, and the US."

'No need to renegotiate Iran deal'

European Union foreign policy chief Federica Mogherini said on Wednesday that there was no need to renegotiate the Iranian nuclear deal, insisting it was “delivering” despite US demands to re-open the agreement.

“There is no need to renegotiate parts of the agreement because the agreement is concerning a nuclear programme and as such is delivering,” Mogherini told reporters following a UN meeting of the six powers that negotiated the deal with Iran.

“We have all agreed that all sides are implementing so far the agreement,” she said.

US Secretary of State Rex Tillerson joined Iranian Foreign Minister Mohammad Javad Zarif for a first meeting with partners backing the 2015 deal that provides for sanctions relief in exchange for curbs on Tehran's nuclear programme.

Trump is due to report to the US Congress by October 15 on whether he can certify that Iran is upholding its side of the accord, under which it accepted limits on its nuclear programme.

In his address to the UN General Assembly, Trump on Tuesday called the nuclear deal “an embarrassment” for the US and Tillerson later confirmed that the agreement must be “revisited.”

But Mogherini, who chaired the meeting, argued that it would be unwise to re-open the deal at a time when the world is facing a nuclear threat from North Korea.

“We already have one potential nuclear crisis. We definitely do not need to go into another one,” she said.

Other than Iran and the US, the other signatories of the accord are Britain, France, Russia, China and Germany.