The 15-member council adopted a US-British resolution that "immediately" shut down the work of the United Nations Monitoring, Verification and Inspection Commission (UNMOVIC).

The text also terminated the mandate of the International Atomic Energy Agency's (IAEA) Iraq Nuclear Verification Office, responsible for dismantling the country's nuclear weapons programme.

UNMOVIC was set up in 1999 to verify that Iraq, under the rule of the late Saddam Hussein, no longer had weapons of mass destruction (WMDs) and had complied with its obligations not to acquire new proscribed arms.

UNMOVIC inspectors pulled out of Iraq on March 18, 2003, immediately before the US-led invasion, and were not allowed to return.

The work of hunting down Iraq's suspected WMDs was then taken over by a US-led coalition body, the Iraq Survey Group, but no weapons were found, seriously undermining what had been the major US and British argument for going to war.

"It's a historic day because it opens a new chapter with regard to Iraq and WMDs," US Ambassador to the UN Zalmay Khalilzad told reporters after the vote.

Iraq's UN envoy Hamid al-Bayati said the resolution would close "an appalling chapter in Iraq's modern history."

He pointed out that Baghdad was now constitutionally committed "to the non-proliferation, non-development, non-production and non-use of nuclear, chemical and biological weapons and associated equipment."

The council vote was 14 in favour with only Russia abstaining.

Russian Ambassador Vitaly Churkin said he abstained because the resolution "does not provide for certification regarding the closing of the Iraqi file."

He cited lingering questions about the fate of Iraqi military items under observation, the stockpile of other weapons and the programme of dual-use weapons.

He said there was still "a lack of clarity about the fate of several dozen Iraqi missiles" which UN inspectors had not been able to destroy.

Khalilzad for his part conceded that while Washington had underestimated Iraq's WMD capability during the first Gulf War in 1991, it overestimated it in the runup to the 2003 war.

In a recent joint letter to the president of the Security Council, the United States and Britain stated that "all appropriate steps have been taken to secure, remove, disable ... eliminate or destroy all of Iraq's known weapons of mass destruction and ballistic missiles with a range greater than 150km."

In line with an Iraqi request, the resolution directs UN chief Ban Ki-moon to transfer to Iraq's development fund all remaining unallocated funds drawn from the country's oil revenues to finance UNMOVIC work.

It also asks the UN chief "to take all necessary measures" to secure UNMOVIC archives and in particular ensure "that sensitive proliferation information or information provided in confidence by member states is kept under strict control."

Washington had for the past two years pressed for an end to all related UN inspection work there.

Demetrius Perricos, the acting UNMOVIC executive chairman, told the council that the resolution "closes a cycle of many years of verification, where the UN showed that it can implement successfully the activities demanded by the international community despite difficulties and frequently a lack of cooperation from the inspected party."

But he warned that "in the present security environment of Iraq, the possibility should not be discounted that non-state actors may seek to acquire toxic agents or their chemical precursors in small quantities."

Perricos cited as an example the recent report use by insurgents in Iraq of toxic industrial chemicals such as chlorine, previously under UN monitoring, combined with explosives for dispersal.

"The possibility of non-state actors (insurgents) getting their hands on other -- more toxic -- agents is real," he added.

UNMOVIC, which by the end of last month had a core staff of 34 professionals from 19 nationalities, spends roughly one million dollars a month.