Iran's ambassador to the International Atomic Energy Agency on Friday rejected the suggestion by the UN atomic watchdog's chief that reviving the 2015 nuclear deal after a new US administration comes to power would require striking a new agreement.
Rafael Grossi, who heads the IAEA that polices Iran's compliance with the nuclear deal, told Reuters on Thursday that there had been too many breaches by Tehran for the agreement to simply snap back into place once US president-elect Joe Biden takes office next month.
Mr Biden has said the United States will rejoin the deal, known as the Joint Comprehensive Plan of Action, "if Iran resumes strict compliance".
After President Donald Trump quit the deal in 2018 and reimposed US sanctions, Iran responded by breaching many of the restrictions imposed to prevent it developing nuclear weapons. The violations include enrichment of uranium beyond levels agreed in the treaty, stockpiling enriched uranium above the permitted limit, and resumption of enrichment activity at its Fordo nuclear facility.
"Presenting any assessment on how the commitments are implemented is absolutely beyond the mandate of the agency and should be avoided," Kazem Gharibabadi, Iran’s ambassador to IAEA in Vienna, tweeted. “@iaeaorg played its part during negotiations on the JCPoA.”
Iranian President Hassan Rouhani, architect of the 2015 deal reached with the US, Russia, France, Britain, Germany and China, has repeatedly said Tehran's nuclear steps were reversible if the United States lifted sanctions and fully respected the pact.
Meanwhile, satellite photos obtained by The Associated Press show new construction activity at the Fordo nuclear site.
Iran has not publicly acknowledged any new construction at Fordo, whose discovery by the West in 2009 came in an earlier round of brinkmanship before world powers struck the 2015 nuclear deal with Tehran.
The purpose of the construction remains unclear, but is likely to trigger new concern over Iran's nuclear activity after it began building at its Natanz nuclear facility following a mysterious explosion there in July that Tehran described as a sabotage attack.
“Any changes at this site will be carefully watched as a sign of where Iran’s nuclear programme is headed," said Jeffrey Lewis, an expert at the James Martin Centre for Nonproliferation Studies at the Middlebury Institute of International Studies who studies Iran.
Iran's mission to the United Nations did not immediately respond to a request for comment from Associated Press. The IAEA also did not immediately respond to a request for comment.
Construction on the Fordo site began in late September. Satellite images obtained from Maxar Technologies show the construction taking place at a north-west corner of the site, near the city of Qom about 90 kilometres south-west of Tehran.
A photo taken on December 11 shows what appears to be a foundation for a building with dozens of pillars.
The construction site sits north-west of Fordo's underground facility, built deep inside a mountain to protect it from air strikes. The site is near other support and research-and-development buildings at Fordo, including the National Vacuum Technology Centre. Vacuum technology is a crucial component of Iran's uranium enrichment centrifuges.