A defiant Mahmoud Ahmadinejad on Sunday dismissed the United Nations Security Council resolution imposing sanctions on Iran over its nuclear program as "a piece of torn paper" that would not deter Iran from its nuclear activities.

"It is a piece of torn paper... by which they aim to scare Iranians... It is in the Westerners' interests to live with a nuclear Iran," the semi-official Fars news agency quoted him as saying.

In his first response since the 15-member Council voted unanimously Saturday to impose economic sanctions, the hard-line Iranian president said that the supporters of the resolution would soon regret their "superficial act," the Irna news agency reported.

"This resolution will not harm Iran and those who backed it will soon regret their superficial act," Ahmadinejad said.

"Iranians are neither worried nor uncomfortable with the resolution... we will celebrate our atomic achievements in February."

Meanwhile, Tehran's chief nuclear negotiator Ali Larijani said that in an immediate response to the resolution, Iran will start installing 3,000 centrifuges at its Natanz uranium enrichment plant.

"From Sunday morning, we will begin activities at Natanz -site of 3,000 centrifuge machines - and we will drive it with full speed. It will be our immediate response to the resolution," Iran's Kayhan newspaper quoted Larijani as saying.

On Saturday, the Security Council voted unanimously to impose sanctions on Iran for refusing to suspend uranium enrichment, increasing international pressure on the government to prove that it is not trying to make nuclear weapons. The resolution, which was sponsored by Britain, Germany, and France, was approved in a 15-0 vote that included a yes vote by Qatar.

International Atomic Energy Agency (IAEA) Director Mohamed ElBaradei said Saturday that his agency is ready to implement the UN Security Council resolution on Iran.

"The agency will implement the relevant parts of the UNSC resolution that relates to its work," the IAEA said. According to diplomats close to the IAEA the resolution "does not ask much" of the UN nuclear watchdog, only to limit its technical cooperation with Iran, excepting fields like food or agriculture.

The IAEA expressed its hope that a diplomatic solution was still possible and a comprehensive agreement could be reached: "The Director General believes that a long term solution to the Iranian nuclear issue has to be based on negotiation and mutual accommodation."

ElBaradei hopes for an agreement allowing for the development of cooperation with Iran based on "mutual respect and the establishment of international confidence in the exclusively peaceful nature of Iran's nuclear program."

Iran defiant in the face of sanctions Iran formally rejected the council's decision, calling the sanctions illegal and vowing to continue its nuclear program. Iran's parliament speaker said prior to the vote that parliament would alter the Islamic Republic's relationship with the UN's International Atomic Energy Agency (IAEA) nuclear watchdog if the sanctions were approved.

Iran's parliament speaker said Saturday that parliament would alter the Islamic Republic's relationship with the UN's International Atomic Energy Agency (IAEA) nuclear watchdog if the sanctions were approved.

"If they intend to deprive the Iranian nation of its certain right to nuclear technology by a resolution... parliament will reconsider the nature of its relationship with the IAEA," Parliament Speaker Gholamali Haddadadel told state television.

The resolution demands Tehran end all research on uranium enrichment, which can produce fuel for nuclear power plants as well as for bombs, and halt research and development that can make or deliver atomic weapons.

The resolution is under Article 41 of Chapter 7 of the UN Charter, which makes enforcement mandatory but restricts action to nonmilitary measures. It would suspend sanctions if Tehran in turn suspended "all enrichment related and reprocessing activities, including research and development."

The thrust of the sanctions is a ban on imports and exports of dangerous materials and technology relating to uranium enrichment, reprocessing and heavy-water reactors, as well as ballistic missile delivery systems.

Iran has vowed to continue its nuclear program, which first came to light in 2002 and Iran says is for peaceful purposes. (Click here for a timeline of Iran's nuclear program)

Before the UN vote on Saturday, acting U.S. Ambassador Alejandro Wolff told the council "Today we are placing Iran in the small category of states under Security Council sanctions."

"We will not hesitate to return to this body to seek further action should Iran fail to comply," Wolff added.

Russia's UN Ambassador Vitaly Churkin, who was successful in watering down parts of the resolution, emphasized however that the resolution did not permit any use of force.

Moscow's earlier hesitation over supporting the resolution prompted a phone call Saturday between U.S. President George W. Bush to Russian President Vladimir Putin, who had reviewed the resolution until the last minute following two months of tough negotiations. Russia is building an $800 million light-water reactor for Tehran that is exempted in the resolution.

Israel: Resolution sends clear message to Iran Defense Minister Amir Peretz welcomed Saturday's UN Security Council decision to impose sanctions on Iran, calling it an important step. Nonetheless, Peretz said, Israel must continue to push for stricter sanctions.

Vice Premier Shimon Peres said the "decision is a small first step, but in the right direction."

"Before going to war it is possible to achieve what we want without war, if the world will take the right steps," continued Peres.

Foreign Ministry spokesman Mark Regev said it sends "a clear message to the Iranian leadership that Iran's nuclear program is total unacceptable and the community of nations will act to prevent the Iranian regime from obtaining nuclear weapons."

The Defense Ministry said the international community "will need to continue to show determination to reach the goal of blocking Iran's nuclear plan."

The U.S. administration said Saturday it hopes the resolution penalizing Iran for its nuclear enrichment program will clear the way for tougher measures against Tehran by individual countries, particularly Russia.

"We don't think this resolution is enough in itself," Undersecretary of State Nicholas Burns said. "We want the international community to take further action. We're certainly not going to put all our eggs in the UN basket."

Iran warning Haddadadel said if the pressure mounts on Iran, parliament will have to discuss a plan, approved by the parliament's national security committee, that wants a serious reconsideration in Iran's relation with the IAEA.

He did not elaborate on the contents of the bill and how it was meant to alter Iran's relationship with the IAEA. Parliament has already banned IAEA snap inspections in February in response to its nuclear case referral to the UN Security Council.

However, the head of parliament's national security committee Alaeddin Boroujerdi said on Saturday that Iran was not interested in quitting the Nuclear non-Proliferation Treaty (NPT) despite possible sanctions.

"Since Iran seriously opposes building nuclear weapons it is not interested in signing out from such an important matter in international aspect," Boroujerdi was quoted by Iran's student news agency ISNA as saying.