Iran has rebuffed a request by the UN nuclear chief for prompt cooperation with a probe into possible military aspects of Tehran’s atomic activities, in a defiant letter underlining increasingly strained ties. The International Atomic Energy Agency (IAEA), the Vienna-based UN nuclear watchdog, is voicing growing concern about allegations Iran may have carried out military-related atomic work — a charge the Islamic Republic denies. IAEA Director General Yukiya Amano wrote to the head of Iran’s Atomic Energy Organisation on May 6, asking Fereydoun Abbasi-Davani to help answer the agency’s queries and provide access to locations, equipment, documents and officials. The IAEA, tasked with ensuring that nuclear technology is not diverted for military aims, says Iran has not engaged with the agency in substance on these issues since mid-2008. For several years, the IAEA has been investigating Western intelligence reports indicating Iran had coordinated efforts to process uranium, test explosives at high altitude and revamp a ballistic missile cone so it can take a nuclear warhead. In a five-page response to Amano’s letter, dated May 26 and obtained by Reuters on Friday, Abbasi-Davani reiterated Iran’s often-stated position that the allegations were “fabricated and acts of forgery”. It gave no indication that Iran would be prepared to heed Amano’s demands, referring instead to a “work plan” agreed between Iran and the agency in 2007, which it said envisaged no inspections, meetings, or interviews with officials.