Mike Pompeo urges UK to help rein in 'lawless' Iran over nuclear deal

US secretary of state Mike Pompeo has urged the UK to stand with Washington in reining in Iran’s “bloodletting and lawlessness”, as Tehran took the first conditional steps to extricate itself from the landmark nuclear deal it had signed with the west, Russia and China in 2015.

Iran said it was acting in response to Donald Trump’s decision a year ago to withdraw the US from the deal known as the Joint Comprehensive Plan of Action, JCPOA, imposing a wave of sanctions not just on Iran but on any company that seeks to trade with it.

While Pompeo was in Britain, Trump announced a new layer of sanctions, this time targeting Iranian metal industries.

The foreign secretary, Jeremy Hunt, said Iran’s decision on Wednesday was unwelcome.

“They need to be very clear that if they do not comply with the JCPOA, there will be consequences,” he said.

“This is a very big moment for Iran. Their economy is a state of severe distress. The last thing they they should be doing is investing money in re-nuclearising. It will make them less secure, not more secure.”

Related: Iran nuclear deal: what has Tehran said and what happens next?

But Hunt’s aides said Tehran’s move did not itself represent a breach of the agreement, nor warrant sanctions. Senior British diplomats are due to travel to Tehran this weekend to urge restraint.

Pompeo described the announcements made by the Iranian president, Hassan Rouhani, as “intentionally ambiguous” and designed to make the world jump – and probably aimed at reducing the “breakout time” by which Iran could secure a nuclear bomb.

Speaking in London, Pompeo minimised differences between the US and the UK over Iran.

“There is no daylight between our two countries on the threat emanating from the Iranian regime,” he said.

“We agree they are operating in defiance of UN ballistic missiles resolution. We agree they fund terror across the Middle East and across the world. We agree they take hostages and repress their own people.”

But Pompeo added: “I urge the UK to stand with us to rein in bloodletting and lawlessness, not to soothe the ayatollahs angry at our decision to pull out of a nuclear deal.”

He implied that if the UK’s true motive in cooperating with Iran was access to new markets, the US and UK could cooperate to find alternatives.

Iran’s phased departure from the deal centres on a threat to enrich its uranium stockpile closer to weapons-grade levels in 60 days’ time if European powers fail to deliver on previous trade promises.

The announcement came against a background of military escalation in the Middle East. The US dispatched an aircraft carrier and bombers to the region earlier this week, claiming it had intelligence of a “credible threat” from Iranian forces.

The US stepped up its pressure on an already reeling Iranian economy. Trump signed an executive order on Wednesday sanctioning the country’s iron, steel, aluminium and copper industries.

“We are successfully imposing the most powerful maximum pressure campaign ever witnessed, which today’s action will further strengthen,” Trump said in a written statement.

The president held out the prospects of new negotiations, but in the framework of 12 wide-ranging conditions the US has laid down for Iran.

“I look forward to someday meeting with the leaders of Iran in order to work out an agreement and, very importantly, taking steps to give Iran the future it deserves,” Trump said.

The US has also blocked the sale of Iranian oil on the global market, depriving Tehran of 40 % of its annual revenue. The value of the Iranian rial has collapsed, fuelling unemployment and inflation.

Meanwhile, the Rouhani government has come under political pressure from hardliners who have long maintained that Iran gave up too much in the nuclear deal.

Rouhani said in a televised address: “We felt that the nuclear deal needs a surgery, and the painkiller pills of the last year have been ineffective. This surgery is for saving the deal, not destroying it.”

The first step, Rouhani said, was to end the sale of excess uranium and heavy water, a move that will increase Iran’s stocks of both above levels stipulated in the deal.

The move was partially forced on Iran by the US decision last week to end waivers allowing Iran to exchange its enriched uranium for unrefined yellowcake uranium from Russia, and to sell its heavy water – used as a coolant in nuclear reactors – to Oman.

If no new deal is in place within 60 days, Iran will increase its enrichment of uranium beyond the 3.67% permitted in the accord, which can fuel a commercial nuclear power plant.

Rouhani did not identify the level to which Iran would be willing to enrich, although the head of Iran’s nuclear program again reiterated that it could reach 20% enrichment within four days.

Scientists have said that once a country enriches uranium to about 20%, the time needed to reach the 90% threshold for weapons-grade uranium is halved.

Rouhani also said that if the 60 days pass without action, Iran will halt a Chinese-led effort to redesign its Arak heavy water nuclear reactor. Such reactors produce plutonium that can be used in nuclear weapons.

Iran notified Britain, Russia, China, the European Union, France and Germany of its decisions earlier on Wednesday. Iran said it will not need to take the steps if countries “join negotiations and help Iran to reach its benefits in the fields of oil and banking”.

It is not clear if Europe has either the means or the will to engineer a mechanism that truly protects European traders dealing with Iranian banks from the threat of US sanctions.

Pompeo said it would be legitimate for Europe to trade humanitarian supplies with Iran since they are exempt from sanctions, but they remained the only items exempt from US treasury oversight.

Israel’s prime minister, Benjamin Netanyahu, a fierce opponent of Iran and the nuclear deal, said: “I heard that Iran intends to continue its nuclear program. We will not allow Iran to obtain nuclear weapons.

“We will continue to fight those who seek to take our lives, and we will thrust our roots even deeper into the soil of our homeland.”