U.N. council must increase sanctions on Iran: U.S

By Louis Charbonneau

UNITED NATIONS (Reuters) - The United States said on Sunday that Iran has left the U.N. Security Council no choice but to increase sanctions on the Islamic Republic for ignoring demands that it halt sensitive nuclear activities.

The U.S. declaration came a day after an informal deadline lapsed for Iran to respond to an offer from the United States, Britain, France, Germany, China and Russia for talks on its disputed nuclear program.

"It is clear that the government of Iran has not complied with the international community's demand to stop enriching uranium and isn't even interested in trying," said Richard Grenell, spokesman for the U.S. mission to the United Nations.

"They leave the Security Council no choice but to increase the sanctions, as called for in the last resolution passed."

Tehran has not formally responded to the offer. But Iranian President Mahmoud Ahmadinejad said on Saturday that Iran would not back down in its nuclear dispute with the powers, which have supported three rounds of U.N. Security Council sanctions.

"In whichever negotiation we take part ... it is unequivocally with the view to the realization of Iran's nuclear right and the Iranian nation would not retreat one iota from its rights," Ahmadinejad said in a statement.

The U.S. statement was noticed by oil traders. Concern about Iran's nuclear program was one of the reasons the price of oil rose by more than $1 to over $126 a barrel shortly before 7 p.m. EDT.

The West accuses Iran of seeking to develop nuclear weapons under cover of a civilian power program. Iran, the world's fourth-largest oil producer, says its uranium enrichment drive is aimed solely at generating electricity.