The US has recently shared new sensitive information with the International Atomic Energy Agency on key aspects of Iran's nuclear program that Washington says shows Teheran was directly engaged in trying to make an atomic weapon, diplomats said Thursday. One of the diplomats told The Associated Press that Washington also gave the IAEA permission to confront Iran with at least some of the evidence in an attempt to pry details out of the Islamic republic on the activities, as part of the UN nuclear watchdog's attempts to investigate Iran's suspicious nuclear past. The diplomats suggested that such moves by the US administration would be a reflection of Washington's drive to pressure Iran into admitting that it had focused part of its nuclear efforts toward developing a weapons program. While the Americans have previously declassified and then forwarded intelligence to the IAEA to help its investigations, they do so on a selective basis. Following Israel's bombing of a Syrian site late last year, and media reports citing unidentified US officials as saying the target was a nuclear installation, IAEA chief Mohamed ElBaradei turned in vain to the US in asking for details on what was struck, said a diplomat who - like others - asked for anonymity in exchange for divulging confidential information. Already shared over the past two years by the U.S. was material on a laptop computer reportedly smuggled out of Iran. In 2005, US intelligence assessed that information as indicating that Teheran had been working on details of nuclear weapons, including missile trajectories and ideal altitudes for exploding warheads. After declassification, US intelligence also was forwarded on two other issues - the "Green Salt Project" - a plan the US alleges links diverse components of a nuclear weapons program, including uranium enrichment, high explosives testing and a missile re-entry vehicle, and material in Iran's possession showing how to mold uranium metal into warhead form. Two of the diplomats said the material forwarded to the IAEA over the past two weeks expanded on the previous information from the Americans, but had no additional details. Iran is under two sets of UN Security Council sanctions for refusing to suspend uranium enrichment, which it started developing during nearly two decades of covert nuclear activity built on illicit purchases and revealed only five years ago. Since then, IAEA experts have uncovered activities, experiments, and blueprints and materials that point to possible efforts by Iran to create nuclear weapons, even though Teheran insists its nuclear project is peaceful and aimed only at creating a large-scale enrichment facility to make reactor fuel. Its leaders consistently dismiss allegations that they are interested in enrichment for its other use - creating fissile material suitable for arming warheads. Instead of heeding Security Council demands to freeze enrichment, Iran has expanded its program. On Wednesday, diplomats told the AP that Iran's new generation of advanced centrifuges have begun processing small quantities of the gas that can be used to make the fissile core of nuclear warheads. A recent US intelligence assessment that Iran had a clandestine weapons program but stopped working on it four years ago has hurt Washington's attempts to have the UN Security Council impose a third set of sanctions on Teheran for failing to halt enrichment. Any decision by Washington's to share a new batch of sensitive information with the IAEA would seem to be an attempt to regain the initiative in trying to force Iran to admit to such programs in the past.