In the 20-page letter, Mr Manouchehr Mottaki said Iran will not implement the sanctions resolutions because the UN Security Council went beyond its powers, and its actions are inconsistent with the UN Charter.

The United States, the European Union, Israel and others suspect Iran's goal is to produce nuclear weapons. But Iran insists its programme is aimed solely at producing nuclear energy and has defied the council by stepping up its enrichment activities.

In the letter, Mr Mottaki said repeatedly that Teheran has answered all outstanding questions from the International Atomic Energy Agency and the IAEA 'has repeatedly stated that there is no evidence to prove any diversion of the Iranian nuclear program towards military purposes.'

IAEA chief Mohamed ElBaradei said in a Feb 22 report that his team made good progress in clarifying Iran's past nuclear activities but Teheran had not responded properly to intelligence forwarded by the US and its allies purportedly showing nuclear weapons technology.

Foreign ministers of the six countries that have been in the forefront of efforts to ensure that Iran's nuclear intentions are peaceful - the US, Russia, China, Britain, France and Germany - issued a joint statement to coincide with the council's adoption of a third sanctions resolution on March 3 reaffirming their dual-track approach.

They offered to improve a package of political, security and economic incentives they put on the table in June 2006 if Iran suspends enrichment - but said continued defiance will lead to further measures.

Mr Mottaki responded saying: 'The basic question to ponder is, if the council really believes in negotiation, then, why it raises preconditions for such a negotiation?'

He singled out the United States, Britain, France and Germany for pushing new sanctions for political motives and accused them of 'providing false and erroneous information' to the IAEA concerning Iran's nuclear activities.

'These countries should, as a minimum step, admit their mistakes, apologise to the great nation of Iran, correct their behaviour, and above all, compensate all the damages they have inflicted on the Islamic Republic of Iran,' Mr Mottaki said.

'The Islamic Republic of Iran and its citizens have the right to resort to legal actions to seek redress against the sponsors of these unlawful actions. These countries should accept the responsibility for their actions and must be held accountable,' he said.

UN associate spokesman Farhan Haq said Iran's UN Ambassador Mohammad Khazee delivered Mottaki's letter to Secretary-General Ban Ki Moon late on Tuesday and 'also assured the secretary-general that Iran will cooperate with the IAEA.'

Copies of the letter were also sent to the presidents of the Security Council and the General Assembly.

Mr Richard Grenell, spokesman for the US Mission to the United Nations, was dismissive of Mottaki's letter, saying: 'The UN Charter is perfectly clear on these issues.'

Mr Mottaki's letter offered a rebuttal to every paragraph of the latest sanctions resolution - saying it was illegal to freeze assets and ban travel of Iranians involved in the country's nuclear programme, prevent equipment with both civilian and military uses from entering the country, monitor banks, and search suspected cargo.

Mr Mottaki criticised the 'irrational opposition' of the US and the three EU countries - pointedly leaving out Russia and China who voted for the sanctions resolutions but have close ties to Teheran.

He accused the four Western countries of using the IAEA board of governors and the Security Council 'as a tool for advancing their political intention.'

'They have unfoundedly tried to accuse Iran of concealment, non-transparency and unlawful behaviour, and have even used these allegations as the basis for bringing Iran's nuclear issue to the UN Security Council and adopting unwarranted and unlawful measures in this regard,' Mr Mottaki said.

The sanctions resolutions, he said, have been costly to Iran in many ways - money, the time of its nuclear experts, lost work at nuclear facilities, the release of some unspecified confidential information to the IAEA, and most importantly to Iran's reputation in the international arena.

'These few countries have unfairly and baselessly tried to portray the peace and justice-loving people of Iran as warmonger and have endeavored to tarnish the image of Iran, and indeed all these can be proper grounds to take legal actions by my country and to seek remedy,' Mr Mottaki said.

He said the 'false and erroneous information' from the four countries led the IAEA to spend its resources on Iran for a long time and prevented the agency from addressing important nonproliferation issues including finding a way to verify the nuclear activities of Israel.

He accused 'the Zionist regime' of continuing to develop nuclear weapons. Israel has never acknowledged or denied having nuclear weapons but accuses Iran of seeking them. -- AP