"In December 2002, U.S. officials said that Iran is building two previously unknown nuclear sites at Arak and Natanz, which could be used in a nuclear weapons program. A visit by the International Atomic Energy Agency to the Natanz facility on February 21 found that the facility contained a more advanced uranium enrichment program than was expected. On April 23, Administration officials warned Iran not to meddle in post-Saddam Iraq by supporting Shiite Islamist organizations seeking power there, although without specifically threatening military action if Iran defied the warning."
CRS Issue Brief for Congress, IB93033
United States. Dept. of State. Bureau of Public Affairs. Foreign Press Centers: http://fpc.state.gov/