Iran’s leaders agreed to answer all remaining questions about their country’s past nuclear activities within four weeks in talks with the UN’s chief nuclear inspector, his spokesperson said on Sunday. The spokesperson also said IAEA chief Mohamed ElBaradei received new information on Iran’s “new generation of centrifuges” — a priority as the agency tries to establish how far advanced Iran is in developing the technology, which could be used in a weapons programme.The four-week deadline is meant to wrap up an IAEA probe of past Iranian nuclear programmes. A diplomat familiar with the talks said that investigation now was focused on the most delicate aspects of Iran’s past atomic work, including programs linked to US suspicions the country conducted experiments linked to nuclear arms.The probe was slated to be completed in December, and the US and its allies have been chafing at the delay, say diplomats.