The IAEA received and conveyed to the Board of Governors Iranian notification that “UO2 [uranium oxide] enriched up to 20 per cent U-235 would be shipped to the R&D laboratory at the Fuel Fabrication Plan in Isfahan, where it would be converted to UF4 [uranium tetrafluoride] and then to uranium metal enriched to 20 per cent U-235, before using it to manufacture the fuel”. The E3 jointly expressed “grave concern” at the development, adding that “this further step in Iran’s escalation of its nuclear violations is all the more concerning at a time when no date has been set for the continuation of the negotiations in Vienna… [and] in the context of Iran having significantly curtailed IAEA accesses”. “Iran is threatening a successful outcome to the Vienna talks despite the progress achieved in six rounds of negotiations”, Berlin, Paris and London warned. A U.S. diplomatic spokesperson asserted that “it is worrying that Iran is choosing to continue to escalate its nonperformance of its JCPOA commitments, especially with experiments that have value for nuclear weapons research”. “We have made clear that such provocative steps would not and will not provide Iran with any leverage in negotiations”, he added. “They would only intensify our concerns with Iran’s activities, and we continue to urge Iran to stop this brinksmanship, to return to Vienna prepared for real talks, and to be in a position to be prepared to finish the work that we have started”.