A nuclear official said Friday Iran will not answer to the U.N. nuclear watchdog about its plans to build 10 new uranium enrichment sites beyond the barest minimum required under the international nonproliferation treaty.

The comments by Abolfazl Zohrehvand, an adviser to the country's top nuclear negotiator Saeed Jalili, came days after President Mahmoud Ahmadinejad said Iran was considering whether to scale back cooperation with the International Atomic Energy Agency after it approved a resolution censuring Iran over its nuclear program.

If Iran follows through on the threat, it would be another slap to Western efforts to curtail Iran's nuclear program for fear it is aimed at building weapons.

Tehran on Sunday announced it intends to build the 10 new sites — a statement that followed a strong rebuke from the Vienna-based IAEA and heightened Western concerns over Iran's real nuclear intentions.

Zohrehvand said Iran will only inform the IAEA after it installs equipment at the new sites and no less than six months prior to injecting uranium gas into centrifuges during the enrichment process. Uranium enriched to low levels is used to produce nuclear fuel but further enrichment could produce material for a nuclear weapon.

"We, like other member states, will inform the agency only after installing the equipment and only 180 days before injecting gas," Zohrehvand said, according to the official IRNA news agency.

The IAEA says Iran must provide all information about the new sites as soon as it makes the decision to build them.

The U.N. watchdog demanded Iran immediately cease all enrichment and halt further construction on a recently revealed uranium enriching facility in a mountainous area near the holy city of Qom.

Iran's reaction to the rebuke was to pledge to build the 10 new uranium enrichment facilities — a move some analysts say is bluster. The grandiose scheme is largely impossible as long as sanctions stand in the way and force Iran to turn to black markets and smuggling for nuclear equipment.

The new sites are to be on the same scale as Iran's only other known industrial-level enrichment plant, near the town of Natanz in central Iran.

Iran claims it has fully cooperated with the IAEA under the Nonproliferation Treaty, especially in disclosing the secret site at Qom this fall.

IAEA rules said a country is required to inform the agency about the existence of any enrichment facility six months before it becomes operational. The agency later expanded those rules to demand countries notify it of intentions to build new sites.

Iran says it withdrew in 2007 from that part of the deal and is now only subject to the six-month notification requirement. But the IAEA says Tehran cannot unilaterally withdraw and still should announce plans about new facilities.

Tehran argues its nuclear program is peaceful and insists it has a right to enrich uranium to produce fuel for nuclear reactors to generate electricity. The United Nations has demanded Iran freeze enrichment.

Iran and the West are deadlocked over a U.N. proposal for Iran to send much of its enriched uranium abroad. The plan is aimed at drastically reducing Iran's stockpile of enriched uranium in hopes of thwarting the country's ability to make a nuclear weapon. So far, Iran has balked at the offer.

Ahmadinejad this week also declared Iran would enrich uranium to a much higher level — from current 3.5 percent to 20 percent — a move experts say could put Tehran on the road to making the material needed to arm a warhead within months.

While the announcement on the 10 new sites is seen as an act of defiance rather than a realistic undertaking, any scaling back on cooperation with the IAEA would escalate the standoff.

The U.N. agency's inspectors and monitoring are the world's only eyes on Tehran's program.