Rouhani says if countries still in pact do not protect trade with Iran, Tehran will start to revive Arak after July 7.

Iran threatened to resume building a heavy water reactor in three days unless partners in the nuclear deal protected its trade, as tension over the floundering agreement ratchets up.

President Hassan Rouhani said as required by the historic 2015 accord – abandoned by US President Donald Trump last year – Iran removed the core of the reactor and filled it with cement in January 2016.

“[But] from July 7 onward with the Arak reactor, if you don’t operate [according to] the programme and timeframe of all the commitments you’ve given us, we will return the Arak reactor to its previous condition,” Rouhani warned signatories on Wednesday.

“Meaning the condition that you say is dangerous and can produce plutonium,” he said, referring to a key component of a nuclear weapon.

“We will return to that unless you take action regarding all your commitments regarding Arak.”

Rouhani kept the door open to negotiations, however, saying Iran would again reduce its stockpile of enriched uranium below the 300-kg limit set by the nuclear pact if signatories Britain, France, Germany, Russia and China honoured their pledges.

‘As much as we want’

But he also threatened the further enrichment of uranium if they failed to act.

“On July 7, our enrichment level will no longer be 3.67 percent. We will put aside this commitment. We will increase beyond 3.67 percent to as much as we want – as much as is necessary, as much as we need,” Rouhani said.

Tensions have soared between Washington and Tehran since Trump pulled Washington out of the nuclear deal last year and reimposed sanctions on Iran in a bid to reduce its international sales of oil to zero.

Fears of a military conflict breaking out remain high. The US has rushed an aircraft carrier, B-52 bombers and F-22 fighters to the Gulf region, while Trump said the Iranians were “playing with fire”.

Hesamodin Ashena, President Hassan Rouhani’s adviser, warned Trump against listening to hawks in his administration, hinting aggression against Iran could make him a “one-term president”.

“We have unseated an American president in the past, we can do it again,” he tweeted, referring to Jimmy Carter whose bid for a second term was marred by the Iran hostage crisis in 1980.

‘Go back’

European nations have warned Iran against fulfilling its threats to resume its nuclear programme.

Iran will gain nothing by departing from the terms of the agreement, the French foreign ministry cautioned on Wednesday.

“Putting [the deal] into question will only increase the already heightened tensions in the region,” ministry spokesman Agnes von der Muhll told reporters in a daily briefing.

Rouhani urged Europe and the United States return to the negotiating table.

“Go back to understanding, to respecting the law and resolutions of the UN Security Council,” he said. “Under those conditions, all of us can abide by the nuclear deal.”