The star of a live television interview in Iran's new nuclear workshop wasn't the head of the country's atomic agency, but three centrifuges labeled in English in the background, advanced devices Tehran is prohibited from using by the nuclear deal with world powers.

The placement of the centrifuges, identified as IR-2M, IR-4 and IR-6, may have served as a subtle warning to Europe as it tries to salvage the atomic accord after President Donald Trump's decision to withdraw from it and restore U.S. sanctions.

In recent days Iranian officials from Supreme Leader Ayatollah Ali Khamenei on down have vowed to boost the country's uranium enrichment capacity. The moves they have outlined would not violate the 2015 nuclear accord, but would allow Iran to quickly ramp up enrichment if the agreement unravels.

"I think they've been quite clear in saying that if the U.S. pulls out and the EU doesn't live up to its side of the deal, it will rapidly increase its enrichment capacity," said Ian Stewart, the head of a nuclear proliferation study called Project Alpha at King's College London. "It doesn't mean that it would go for nuclear weapons, but it does mean they could rapidly do that if they chose to do so."

Under the nuclear deal with world powers, Iran accepted limits to its uranium enrichment and gave up its stockpiles in exchange for the lifting of crippling international sanctions. Western nations and Israel have long suspected Iran of covertly seeking a nuclear weapons capability alongside its civilian program. Iran has always insisted its nuclear program is for purely peaceful purposes like electricity and the production of medical isotopes.

In the 2015 agreement, Iran agreed only to enrich uranium up to 3.67 percent, enough to use in a nuclear power plant but far lower than the 90 percent needed for an atomic weapon.

Iran also mothballed much of its centrifuges, the devices it uses to enrich uranium by rapidly spinning uranium hexafluoride gas. Today at Natanz, its main enrichment facility, Iran can run only 5,060 of them. Those centrifuges are models known as IR-1s, based on a 1970s Dutch design that Pakistani scientist A.Q. Khan used to build Islamabad's nuclear weapons program and later sold to Iran, Libya and North Korea.

The IR-2M, IR-4 and IR-6 models are all believed to produce three to five times more enriched uranium in a year than the IR-1s, according to Western anti-proliferation experts.

Ali Akbar Salehi, the head of Iran's nuclear agency, said Wednesday night that the IR-6 is 10 times more effective than the IR-1.

During the live state television interview at Natanz, a nuclear facility with underground bunkers protected from airstrikes, Salehi said a new workshop there that was nearly ready to open could build 60 centrifuges a day. He said it could build all three of the displayed models.

It wasn't clear whether the centrifuges displayed were working models of the IR-2M, IR-4 and IR-6, though they resembled pictures of the three previously circulated by Iranian media.

"The IR-2M and the IR-4 have passed the research and development period and we can mass produce them, but due to the (nuclear deal), we don't do it yet," Salehi said. He said the IR-6 had some faults but could be mass produced after solving them.

Not on display was the IR-8, one of Iran's most advanced prototypes, which Western experts believe is at least 16 times more effective than the IR-1. A 2016 report by Iran's pro-reformist Arman newspaper described the IR-8 as 24 times more effective.

Salehi said the IR-8 was too big to be produced in the new workshop, though another workshop could be built nearby for it. He said that model remained years from mass production.

For now, Iran remains within the terms of the nuclear deal. But if it falls apart, nothing would prevent Iran from immediately using these advanced centrifuges — and potentially raising the risks of a confrontation with the West.

"If you have a smaller number of very advanced centrifuges, it's easier for you to enrich in a secret location," Stewart said.

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Associated Press writer Mehdi Fattahi in Tehran, Iran, contributed to this report.

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