Iran has admitted a further breach of the 2015 nuclear deal by firing up advanced uranium-enriching centrifuges installed at its underground plant at Natanz. The finding was made by the UN nuclear weapons inspectorate, the International Atomic Energy Association, and confirmed by the Iranian ambassador to the IAEA. Donald Trump last week considered but rejected a military strike on Natanz, south of Tehran and the country’s main uranium-enrichment site. But the latest move by Iran may be regarded by his administration as a provocation that changes his, or Israel’s, calculation of risk. The development comes weeks ahead of him standing down and being replaced by Joe Biden, who is committed to re-entering the nuclear deal struck under Barack Obama. According to the 2015 Iran nuclear deal, the Islamic Republic can only accumulate enriched uranium with first-generation IR-1 machines, which are the only ones it is permitted to operate at the underground plant. But the IAEA report said that Tehran had been feeding uranium hexafluoride (UF6) gas feedstock into advanced IR-2m machines. A previous IAEA report said that Iran had installed the IR-2m machines underground. And in its latest report, dated Tuesday, the IAEA states: “On 14 November 2020, the Agency verified that Iran began feeding UF6 into the recently installed cascade of 174 IR-2m centrifuges at the Fuel Enrichment Plant (FEP) in Natanz.” The previous report was based on a visit to the plant on 2 November before Biden had been elected, but this latest assessment is based on Iranian actions after Biden’s victory. Iran has been steadily breaching limits set in the nuclear agreement in what it portrays as a calculated and justified response to the US decision to quit the deal, (known as the Joint Comprehensive Plan of Action, or JCPoA), impose crippling sanctions and punish European companies that seek to trade with the country. Iran had previously informed the agency that it would transfer three cascades of the uranium-enriching machines from an above-ground pilot plant at the Natanz nuclear site to the underground one. It did so after the above-ground centrifuge workshop exploded in an apparent act of sabotage. The explosion was attributed to a fire, but it was unclear if Israel had been involved. So far, Iran is only using 174 of its IR-2ms, of which it has far more than 1,000. The deal allows Iran to use about 6,000 IR-1s. If Tehran keeps the number of IR-2ms in use low, and even if it at some point installs other more advanced centrifuges but also keeps their numbers low, it could credibly argue it is simply trying to restore what it had above ground prior to the sabotage on 2 July of its previous Natanz facility. The IAEA declared last week that Tehran’s explanations were unsatisfactory for how and why certain nuclear program-related particles were found by agency inspectors at sites where they should not have been present. In a lengthy interview published on Tuesday the Iranian foreign minister, Javad Zarif, clarified Iran’s approach to talks with a Biden administration. He said: “If the US implements its commitments under the UN security council resolution 2231, we will implement our commitments under the JCPoA. This can be done automatically and needs no negotiations. But if the US wants to rejoin the JCPoA then we will be ready to negotiate how the US can re-enter the deal.” Zarif’s wording suggests that as soon as the US lifts its sanctions on Iran the country will come back into compliance with the JCPoA and stop breaching the uranium enrichment limits. But Zarif is resisting allowing the US back into the deal until it has assurances that as a JCPoA member the US will not use its right unilaterally to declare Iran in breach of the deal’s terms, and so require the UN as a whole to reimpose UN sanctions on Iran. The tussle with America is being held against an increasingly grim backdrop of mounting deaths across Iran due to the spread of coronavirus. Health officials announced on Wednesday that a record 13,421 new patients had been identified in the previous 24 hours and a further 480 people had died. The official total death toll stands at 42,941. The spiral in new infections suggests the death toll will continue to mount.