Paris : Iran will gain nothing by departing from the terms of its nuclear agreement, said the French foreign ministry on Wednesday, responding to Tehran’s declaration that it will boost the enrichment level of its uranium.

Iranian President Hassan Rouhani earlier said Iran would raise its uranium enrichment after July 7 to whatever levels it needs beyond the 3.67 per cent purity cap set in the 2015 deal.

The comments came as Boris Johnson, who could be Britain’s prime minister by the end of the month, said the 2015 nuclear deal was “looking increasingly frail” and urged “Iran not to go forward with a nuclear weapons programme”. “I would urge again the Iranian government to think very, very hard about ... breaching their commitments on the Iran nuclear deal. I think they should stick with it and I think it would be a great mistake now for Iran to abandon that approach of restraint and go for enrichment of nuclear materials. I think that would be a serious error.”

Iran ignored US and EU warnings Wednesday and announced it will exceed the maximum enrichment level it agreed for uranium within days in response to the failure of the other parties to a 2015 nuclear deal to provide it with promised relief from sanctions.

Iran is acting on its May 8 threat to suspend parts of the agreement in response to US President Donald Trump’s reimposition of crippling sanctions after withdrawing from it in May last year.

“On July 7, our enrichment level will no longer be 3.67 per cent. We will put aside this commitment. We will increase (the enrichment level) beyond 3.67 per cent to as much as we want, as much as is necessary, as much as we need,” Rouhani said during a cabinet meeting on Wednesday.

The enrichment maximum set in the agreement is sufficient for power generation but far below the more than 90 per cent level required for a nuclear warhead.

Rouhani stressed that Iran’s action would be reversed if the other parties to the nuclear deal made good on their side of the bargain - relief from sanctions.

“We will remain committed to the (nuclear deal) as long as the other parties are committed. We will act on the JCPOA 100 per cent the day that the other party acts 100 per cent (too).”

Iran has sought to pressure the other parties - Britain, China, France, Germany and Russia - to save the deal.

It announced on May 8 it would no longer respect the limits set on the size of its stockpiles of enriched uranium and heavy water.

It threatened to abandon further nuclear commitments, including exceeding the agreed uranium enrichment maximum from July 7.

Rouhani said Iran will also deliver on its threat to resume construction of a heavy water reactor after July 7 and will bring it to the condition that “according to you, is dangerous and can produce plutonium.”

He added the measures can be reversed in “hours” if the other parties “live up to their commitments.”