WASHINGTON - International inspectors visiting Iran last week were shown a network of sophisticated machinery to enrich uranium, spurring concerns that Iran is making headway in its suspected program to develop nuclear weapons, Western officials and international diplomats said yesterday.
The site in question, near the city of Natanz, was visited Friday by Mohamed ElBaradei, the chief of the International Atomic Energy Agency, who went to Iran to assess the status of its nuclear program. It was the first time that inspectors have visited the installation.
During the visit to the Natanz site, inspectors found that it includes a small network of centrifuges for enriching uranium. The inspectors also learned that Iran has components to make a significant number of additional centrifuges.
American officials believe that Natanz is part of a long-suspected nuclear weapons program, an Iranian project that American intelligence believes has benefited from assistance from Pakistan and that is far more advanced than the effort launched by Iraq.
They say Iran's goal is to mine or purchase uranium, process the ore and enrich it to a purity suitable for making weapons - a process that would give Iran a largely indigenous capability to make nuclear weapons.
Iran insists that its aim is to make fuel for a civilian nuclear power program and maintains that it is opening its plant in Natanz to the atomic energy agency to demonstrate its peaceful intentions.
Yesterday, the Associated Press reported, Iranian officials told ElBaradei that they would provide any information sought about the facility's design.
The new data on Iran's program comes at an awkward time for the Bush administration, which is making final preparations for a potential American-led invasion to topple the government of Saddam Hussein, an action justified partly on grounds that Iraq is seeking to develop nuclear weapons.
Pointing out that North Korea's and Iran's nuclear programs are ahead of Iraq's, critics of the Bush administration have contended that it has focused too much on a lesser proliferation problem. Bush administration officials say it is important to act before Iraq becomes a nuclear power and say that the United States is trying to devise different strategies to try to head off North Korea's and Iran's nuclear weapons programs.
ElBaradei, who had planned to visit Iranian sites for three days, cut short his visit to Iran and left yesterday.