Stagnating talks to revive a nuclear deal between Iran and the US have been hit with what has been described as a “fatal blow” after Tehran removed 27 cameras from it’s main facilities, shutting down a monitoring capacity that had been central to hopes of a new pact. Iranian officials said the move was in response to censures led by Europe and Washington for failing to cooperate with the UN nuclear inspectorate, in what Tehran says is a proportionate response to increasing US sanctions. The impasse is potentially the most serious blow yet to President Joe Biden’s attempts to restart a deal that would unlock crippling sanctions reimposed by Donald Trump in return for limiting its nuclear activities and committing to transparent supervision of its contentious programme. It comes amid sharply heightened rhetoric this week from the UN’s nuclear watchdog, which claims Iran has built up large stockpiles of enriched uranium, which is needed for a civilian nuclear programme. It said the country may be only weeks away from producing enough material to make a nuclear bomb. The retention of cameras had been a central demand of western states, and their removal underscores the increasing brinkmanship between the two sides, whose positions appear evermore divergent as a deadline for an agreement draws near. Iran said it had also installed additional centrifuges to enrich uranium. There has been little progress in talks since March, raising tensions at the International Atomic Energy Agency (IAEA) and in Washington, where Biden is facing increasing pressure within his own party over his commitment to concluding a deal. The censure motion was passed by 30 of 35 IAEA members, with only Russia and China voting against. It was the first rebuke to Iran in two years, signalling growing frustrations by states that see a deal slipping away as rival sides remain locked into their positions. The three European signatories – the UK, France and Germany – said in a statement on Wednesday: “Iran’s nuclear advances are not only dangerous and illegal, they risk unraveling the deal that we have so carefully crafted together to restore the nuclear deal. The more Iran is advancing and accumulating knowledge with irreversible consequences, the more difficult it is to come back to the deal.” The IAEA chief, Rafael Grossi, said on Thursday that the time to conclude an arrangement was slipping away. “What we have been informed is that 27 cameras … are being removed in Iran,” he told reporters. “So this of course poses a serious challenge to our ability to continue working there.” Grossi gave a three- to four-week window for a deal to be concluded, describing a failure to do so as a “fatal blow”. A further 40 monitoring cameras remain in Iran and have not yet been switched off. Observers believe their ongoing use is likely to be further leverage for Iranian officials, who have taken a maximalist stance as talks have ground to a halt. The IAEA chief’s recent visit to Israel provoked anger in Iran, which accused the organisation of following the cues of its arch foe. Israel has stridently warned that Iran continues to develop a nuclear programme despite being hit with sanctions. Israel’s prime minister, Naftali Bennett welcomed this week’s censure. “We see here a firm stance by the countries of the world regarding the distinction between good and evil, as they clearly state that Iran is concealing things,” he said. The US state department described the Iranian move to withdraw surveillance cameras as “extremely regrettable”. Israel has led a series of efforts to cripple Iran’s nuclear capability, assassinating nuclear scientists, repeatedly bombing facilities and raiding a warehouse that held data on the programme. Its air force held the largest exercise of its kind last week in Cyprus, simulating mass bombing raids in what analysts suggest could be a dress rehearsal for any such raid in Iran. Iran has insisted on its Islamic Revolutionary Guards Corps, a branch of its armed forces, being removed from the US terrorism watch list – a move that has met fierce opposition among the Gulf states and Israel. It has maintained it has a right build a civilian nuclear programme, which it denies is cover for producing weapons.