Iran's nuclear program, which the country's leaders say is intended solely to generate energy, is under the scrutiny of inspectors from the United Nations International Atomic Energy Agency, Defense Secretary Robert Gates said, Bloomberg reported..
"The real threshold is when will they have enough low- enriched uranium to make it worth their while to throw out the IAEA and then enrich that uranium to weapons-grade so that they would have several weapons," Gates said. The question, he said, is "At what point could they do that?"
Iran also would need to develop a weapon to employ the uranium.
Still, the window of time in which Iran might achieve a nuclear weapon remains one to three years, Gates said, declining to comment on overt or covert efforts to throw a wrench into the program.
U.S. officials, including Secretary of State Hillary Clinton, have said international sanctions and technical difficulties have slowed Iran's nuclear progress.
Iranian nuclear program has caused concern since 2003, when the IAEA became aware of its concealed activity. In late 2003, Iran signed the Additional Protocol to the Treaty on the Nonproliferation of Nuclear Weapons and voluntarily announced about the suspension of uranium enrichment. However, it returned to this activity.
Iran has repeatedly stated that its nuclear programme is for peaceful purposes of providing energy, but many other countries contend that it is seeking to develop nuclear weapons and last June the Security Council imposed a fourth round of sanctions against it, citing the proliferation risks of its nuclear programme and its continued failure to cooperate with the IAEA.