Sanctions include travel ban on certain officials and freezing of more assets.
The Security Council tightened UN sanctions on Iran Monday for refusing to halt nuclear fuel work as six major powers offered to resume talks with the Islamic republic to end the standoff.
Fourteen of the council's 15 members voted in favor of Resolution 1803, sponsored by Britain, France and Germany, which slapped a third set of economic and trade sanctions on Iran in 15 months.
Indonesia abstained during the vote which was presided over by Russia, the council chair for March.
But Libya, South Africa and Vietnam, which joined Indonesia in expressing reservations about the need for fresh sanctions at a time when Iran is cooperating with the International Atomic Energy Agency (IAEA), voted in favor in the end.
After the vote, the six powers trying to scale back Iran's nuclear ambitions issued a statement calling for new talks between EU foreign policy chief Javier Solana and Iran's nuclear negotiator.
"We have asked Javier Solana to meet with Dr. Saeed Jalili, Secretary of Iran's Supreme National Security Council," British ambassador John Sawers said on behalf of Britain, China, France, Germany, Russia and the US.
The six reconfirmed and pledged to expand a 2006 offer of economic and trade incentives to Iran in exchange for a freeze of its uranium enrichment activities which the West fears is aimed at developing nuclear weapons.
US State Department spokesman Tom Casey said his government was "pleased to see the Security Council has recognized the continuing threat posed by Iran's nuclear program through this vote on additional sanctions".
Speaking ahead of the vote, Iran's UN Ambassador Mohammad Khazaee blasted what he called an "unjust and irrational decision" which he said "undermines the integrity and credibility" of the council.
Accusing the resolution's Western sponsors of pursuing "a politically motivated agenda", he said his country would not comply with demands it views as not "legitimate".
"Any irrational and unlawful act will not help resolve Iran's nuclear issue. It will complicate the dealings around this issue and it will become more difficult," said Iran's Atomic Energy Organisation deputy head Mohammad Saeedi.
The Security Council vote came as IAEA chief Mohammed ElBaradei pressed Iran to clear up allegations that it was involved in covert nuclear weapons work.
"I urge Iran to be as active and as cooperative as possible in working with the agency to clarify this matter of serious concern," ElBaradei told the IAEA's 35-member board of governors in Vienna.
The resolution gives Iran three months to comply with UN and IAEA demands to suspend uranium enrichment and reprocessing to help restore international confidence in the peaceful nature of its nuclear programme or face new sanctions.
It includes an outright ban on travel by officials involved in Tehran's nuclear and missile programmes, and broadens a list of individuals and entities subject to an assets freeze.
It calls for inspections of shipments to and from Iran if there are suspicions of prohibited goods and urges states to "exercise vigilance" in entering into new commitments for public-provided financial support for trade with Iran, including the granting of export credits.
It also urges vigilance in dealing with "all banks domiciled in Iran, in particular Bank Melli and Bank Saderat and their branches and subsidiaries based abroad".
In Paris, the French Foreign Ministry said "sanctions are not an end in themselves" and urged Iran to seize on the incentives offered by the six powers in 2006 "to achieve a solution in the interest of all".
German Foreign Minister Frank-Walter Steinmeier welcomed the resolution as a "sign of the international community's resolve". So did Israel, Iran's arch-enemy.
"Iran's leaders threaten the existence of Israel," said Israeli Foreign Ministry spokesman Arye Mekel. "The international community has shown that it has no confidence in Iran when it says it wants to continue its nuclear program for civilian purposes."