A US think-tank says Iran may have violated last year's interim nuclear deal with world powers by stepping up efforts to develop a machine that could enrich uranium faster, but another expert group said it saw no breach.
Iran's development of advanced enrichment centrifuges is sensitive because, if successful, it could enable the country to produce potential nuclear bomb material at a rate several times that of the decades-old model now in use.
Western officials were not immediately available to comment on the allegation by the Washington-based Institute for Science and International Security (ISIS), which closely tracks Iran's nuclear program. There was no immediate comment from Tehran.
ISIS, whose founder David Albright often briefs US lawmakers and others on nuclear proliferation issues, cited a finding in a new report by the International Atomic Energy Agency (IAEA) about Iran.
The confidential document, issued to IAEA member states on Friday, said Iran since the UN agency's previous report in September had "intermittently" been feeding natural uranium gas into a single so-called IR-5 centrifuge at a research facility.