The UN nuclear watchdog has expressed serious concern at Iran’s failure to grant it access to two suspect locations for more than four months. The International Atomic Energy Agency (IAEA) said Iran had blocked inspections at two locations that it believed were active long before the internationally brokered 2015 deal to curb Iran’s nuclear program. According to the report, the agency has questions regarding the possible “use or storage of nuclear material” at the two sites and claims that one of them “may have been used for the processing and conversion of uranium ore including fluorination in 2003.” In an unreleased report expected to be published mid-June the Vienna-based IAEA expresses “serious concern” that the agency was barred from entering the sites. The nuclear watchdog also said Tehran had not clarified its response to their questions related to possible undeclared nuclear material and nuclear-related activities. In a separate report, the agency also noted that as of May 20 Iran had a stockpile of 1,571.6 kilograms of low-enriched uranium, nearly eight times the 202.8 kilogram limit agreed as part of the 2015 nuclear deal. Iran has rapidly accumulated uranium in 2020, with their stockpile growing by 550 kilograms since Feb. 19. The stockpile’s highest level of enrichment now stands at 4.5 percent — breaching the 2015 agreement’s 3.67 percent limit. In July 2015, Iran signed the Joint Comprehensive Plan of Action with the US, Germany, France, Russia, China and the European Union, which curbed Iran’s nuclear weapons program in return for economic incentives. Under the deal, Tehran agreed that “under no circumstances will Iran ever seek, develop or acquire any nuclear weapons.” Iran also agreed to a monitoring regime that would allow international inspectors to gain access to sites suspected of nuclear weapons-related activities. The IAEA’s latest findings come amid heightened tensions between Iran and the USA, which withdrew from the deal, with President Trump calling it the “worst deal ever.”