As Iran maintained its defiance announcing plans for 10 new uranium enrichment facilities, the US on Monday said such a step will be a "serious violation" of its international obligations and will further isolate it.

"If true, this would be yet another serious violation of Iran's clear obligations under multiple UN security council resolutions, and another example of Iran choosing to isolate itself," White House Press Secretary Robert Gibbs said.

His comments came after Iran's state television reported yesterday that the cabinet ordered construction to begin at five new sites earmarked for enrichment plants and asked officials to locate sites for another five such facilities.

"The international community has made clear that Iran has rights, but with those rights come responsibilities. As the overwhelming IAEA board of governors vote made clear, time is running out for Iran to address the international community's growing concerns about its nuclear programme," Gibbs said.

Iran said the announcement has been made in retaliation to a resolution passed last week by the International Atomic Energy Agency, which censored Iran for a newly discovered enrichment site in Qom -- kept secret until recently.

Friday's IAEA resolution saw China and Russia, which have close links with Tehran, join Britain, France, Germany and the USt in condemning Iran over the plant. India also voted in favour of the measure that demanded that Iran should immediately suspend construction of Qom site.