Iran has agreed to answer allegations that it studied how to design nuclear weapons, the chief of the UN nuclear monitoring agency said Apr 23. The official, Muhammad ElBaradei of the International Atomic Energy Agency, called the gesture a milestone. Iran has previously denied the intelligence

reports and declined to address them in detail. Resolving whether Iran has secretly tried to "weaponize" nuclear materials is crucial to winding up an IAEA inquiry into the Islamic Republic's nuclear program. The UN has imposed sanctions against Iran because of suspicions of a covert quest for bombs. The newly announced agreement "is a certain milestone, and hopefully by the end of May we'll be in position to get the explanation and clarification from Iran as to these alleged studies", ElBaradei said during a visit to Sarajevo. "This, in my view, is a positive step". His spokeswoman said the deal had been struck during meetings in Tehran on Monday and Apr 22 between Iranian leaders and Olli Heinonen, the IAEA safeguards chief and top investigator. The IAEA did not elaborate. Iran had called the talks with Heinonen "positive" but had not said what they involved. Iran has rejected the intelligence about weapons experiments as fabricated. It said that earlier exchanges with the IAEA had resolved the issue and that there would be no more discussions. But the IAEA has insisted that Iran back up its denials with proof. US intelligence findings said Iran had researched bomb designs until 2003, and other countries say they believe that the illicit work continued more recently. An unidentified Iranian official in the delegation that met Heinonen did not mention the deal in remarks issued by the official news agency IRNA. "Iran's door is open for negotiations with IAEA legal representatives and Iran will continue its cooperation with the agency like before", the official said. Iran says its nuclear campaign aims solely to generate an alternative source of electricity so that it can export more of its oil and gas. It is the world's No. 4 oil exporter. But Iran's history of nuclear secrecy and continued restrictions on IAEA inspections fan Western suspicions that the underlying purpose of its efforts to industrialize uranium enrichment is the ability to assemble atomic weapons. Iran is under sanctions for refusing to suspend the work. Diplomats said the point of Heinonen's trip was to push for Iranian responses to the intelligence reports, which indicated that Iran linked projects to process uranium, test high explosives and modify a missile cone in a way suitable for a nuclear warhead. Western powers on the IAEA's 35-country board of governors have accused Iran of evasive tactics that dragged out agency inquiries for years before it supplied explanations that allowed the agency to resolve other questions over the past six months. ElBaradei is due to issue a quarterly report on Iran in late May, shortly before an IAEA governors' meeting. The IAEA information, which remains unverified, comes from an Iranian defector's laptop computer that was handed to the US in 2004, intelligence from some other Western sources and from investigations by inspectors.