Iran’s foreign minister has said the country is willing to formally accept a tougher nuclear inspection regime in six years. However, Mohammad Javad Zarif continued to rule out any renegotiation of the 2015 nuclear deal which President Donald Trump last week called “an embarrassment” to the US in a bellicose address to the UN General Assembly.

Bloomberg reported Zarif - who rebuked Trump’s speech at the UN as “primeval” - as on September 27, in an interview with Charlie Rose at the Asia Society in New York, stating: “If Congress behaves, in six years from now, we will be ratifying the Additional Protocol, the most intrusive inspection regime that is available.” He added: “We will become a party to the Additional Protocol, provided the US takes care of its responsibilities.”

Zarif was referring to a wider, more intrusive but voluntary, inspection regime applied to nuclear facilities run by the International Atomic Energy Agency (IAEA).

In mid-October Trump must decide whether to again “certify” Iran’s compliance with the nuclear deal. Each issued compliance lasts for 90 days. Trump has twice previously signed off on compliance, but he has indicated that he will not be doing so a third time. If he does not, the issue of Washington continuing to accept the nuclear agreement will be passed to Congress.

All other major powers have remained supportive of the deal, which removed international economic sanctions applied to Tehran in return for a drastic scaling down of Iran’s nuclear programme. They say there is no indication that Iran is breaching its terms and thus moving towards developing a nuclear bomb. However, Trump is dissatisfied with the agreement because it does not address matters such as the Iranian ballistic missile development programme and Tehran’s involvement in conflicts in the Middle East, such as those in Syria and Yemen.

On September 26, the top US military officer, chairman of the Joint Chiefs of Staff Marine Corps General Joseph Dunford, told the Senate Armed Services Committee that Iran was complying with the nuclear accord and warned that any American decision to quit it would make other countries less likely to enter into such agreements with Washington.

The committee’s top Democrat, Senator Jack Reed, quizzed Dunford on whether ending US participation in the nuclear deal would affect the US ability to negotiate with North Korea over its nuclear weapons and intercontinental ballistic missiles programme or devise a non-military solution towards Pyongyang.

“It makes sense to me that our holding up agreements that we have signed, unless there is a material breach, would impact on others’ willingness to sign agreements,” Dunford said. But he added: “Iran is projecting malign influence across the Middle East, threatening freedom of navigation, while supporting terrorist organisations in Syria, Iraq and Yemen.”