TEHRAN, Iran - Iran announced Sunday that it was partially suspending cooperation with the U.N. nuclear watchdog while hardline President Mahmoud Ahmadinejad said the latest U.N. sanctions would not halt the country's uranium enrichment "even for a second."

Iranian state television quoted Ahmadinejad as saying the additional Security Council sanctions imposed on Saturday "stem from the hostility by some powers against Iran."

"It is not a new issue for the Iranian nation. Enemies of the Iranian nation have made a mistake this time too," Ahmadinejad said, adding the new sanctions "will not halt Iran's peaceful nuclear program even for a second."

Meanwhile, government spokesman Gholam Hossein Elham said the Cabinet on Sunday decided to suspend "code 1-3 of minor arrangements of the safeguards" with the Vienna-based U.N. nuclear watchdog, the International Atomic Energy Agency.

The suspension would "continue until Iran's nuclear case is referred back to the IAEA from the U.N Security Council," Elham said.

Tehran's scaling back of cooperation with the IAEA was in apparent retaliation for the sanctions unanimously approved by the Security Council over Tehran's refusal to stop enriching uranium, a process that can be used in the production of nuclear weapons.

The West strongly suspects Iran's nuclear activities are aimed at producing weapons though Tehran says they are exclusively for the production of energy.

The U.N. sanctions are meant to send Tehran a strong message that its defiance will leave it increasingly isolated and open to even tougher penalties.

But Iran remains defiant. The suspension was a response to "Saturday night's illegal and bullying resolution by Security Council," said Elham, adding the government was acting fully within law in the move.

In New York, Iranian Foreign Minister Manouchehr Mottaki said "a few select countries don't have the right to abuse the Security Council" and described the new sanctions as "illegal, unwarranted and unjustified." He said they undermine the credibility of the Security Council.

Mottaki said Iran has repeatedly sought negotiations with the powers that drafted the resolution against his country: the five permanent council members -- the U.S., Britain, France, Russia and China -- and Germany. But he accused them of lacking the political will to reach a breakthrough.

"If this political will existed, the other side wouldn't have imposed preconditions on the talks," Mottaki said, referring to demands by the U.S. and its allies that Iran first halt enrichment before they engage in negotiations on its nuclear program.

Mottaki said the world has two options to proceed on the nuclear issue: continued negotiations or confrontation and the resolution was the wrong choice.

"Of course, it will have its own consequences," he said.

In Tehran, citizens brushed off news of the latest sanctions.

"Why should we care about sanctions?" asked Ali Reza, a 21-year-old shopping for a digital camera Sunday with his girlfriend. "We've become accustomed to this kind of news. As long as I can remember, there have been such reports in the air."

Saeed Laylaz, an Iranian political commentator, said that until the sanctions hit normal Iranians like Reza -- and the drafters of the U.N. resolution went to great pains to point out that they did not -- Iranians would continue to shrug them off.

"Neither Western people nor Iranians would benefit from such confrontation," said Lida Anvari, who was jogging with her husband in a downtown park. Her husband nodded in agreement, and both said they were fed up with the news.

Elham said that until now, Iran's cooperation with the IAEA went beyond requirements under the Nuclear Nonproliferation Treaty, which Iran is a signatory to. He added that Iran has in the past promptly informed the IAEA about its nuclear plans.

It was not immediately clear what the suspension of cooperation would entail.

Under Iran's Safeguards Agreements with the IAEA, part of its commitments under the Nuclear Nonproliferation Treaty, Tehran is obligated to report to the agency six months before it introduces nuclear material of any kind into any facility.

Beyond that, Tehran has committed itself to informing the agency of any planned new nuclear construction before such construction begins -- a commitment it has not always kept. For instance, Tehran delayed informing the agency three years ago that it was building tunnels in the central city of Isfahan to house parts of its uranium enrichment program.

Former U.N. nuclear inspector David Albright said Sunday's decision could clear the path for Iran to do clandestine nuclear work related to its enrichment program -- a possible pathway to nuclear arms.

Albright, whose his Washington-based Institute for Science and International Security tracks Iran's nuclear program, said that Iran may be looking to build a "backup facility" for enrichment that would remain undetected -- and safe -- in case of attack by the United States or Israel.

IAEA officials were not immediately available for comment.

The new, moderately tougher sanctions on Tehran include banning Iranian arms exports, and freezing the assets of 28 people and organizations involved in Iran's nuclear and missile programs. About a third of those are linked to the Revolutionary Guard, an elite military corps that answers to Tehran leadership.

They also ask countries to restrict travel by the individuals subject to sanctions, as well as arms sales to Iran and new financial assistance or loans to the Iranian government.

The measure also said all sanctions would be suspended if Iran halts enrichment and made clear that the country can still accept a package of economic incentives and political rewards offered last year if it complies with the council's demands.