Khamenei's intervention on a major Muslim holiday -- which also confirmed he was in good health despite rumours otherwise -- was his first official reaction to the UN Security Council's move in December to impose sanctions on Tehran.

"The Iranian nation undoubtedly will not refrain from their right (to nuclear energy) and the country's officials do not have the right to refrain from the nation's rights," Khamanei said in a speech on state television.

The UN Security Council imposed its first ever sanctions on Iran over Tehran's failure to heed calls to suspend uranium enrichment, a process that can be used both to make nuclear fuel or a nuclear bomb.

Iran vehemently denies charges that it is seeking nuclear weapons, insisting that it wants to enrich uranium only for peaceful nuclear energy.

In an angry blast against the governments in London and Washington, Khamenei also warned Arab countries against making any alliance with Britain and the United States over the nuclear issue.

"If the Americans, British and one or more Arab countries sit down and discuss Iran's nuclear energy to see whether not to allow it or approve it or relieve Israel's concerns in this regard, this would be a political mistake" by Islamic governments, he said.

"The Islamic countries' statesmen, especially those in the region, should know that Islam's glory and the Islamic republic's power are a support for them," Khamenei said.

British Prime Minister Tony Blair in December called on "moderate" Arab states to form an alliance against the Islamic republic's alleged support of extremism, in comments angrily condemned by Iranian officials.

"This alliance, with the cooperation of two dirty and sinister governments, is against a nation that Islam is proud of -- a nation that has sacrificed a lot. Therefore Arab countries must be careful about this dangerous trap," said Khamenei.

Monday's broadcast showed Khamenei to be in apparent good health, scotching rumours that surfaced Thursday when a US neoconservative academic's website claimed that he had died.

On Sunday the foreign ministry dismissed the rumours, saying Khamenei was "in good health".

Khamenei, 67, who has the final say on foreign policy and military matters, has been Iran's supreme leader since 1989.

Iranian officials have not signalled any change in nuclear policy since the resolution and the country has instead vowed to press its atomic plans harder than before.

Iran's conservative-dominated parliament adopted a bill requiring the government to "revise" its cooperation with the UN nuclear watchdog which could limit UN inspections of Iran's nuclear sites.

It remains unclear how far the government wishes to change its cooperation with the International Atomic Energy Agency (IAEA) but a militia officer on Monday raised the spectre of using the so-called "oil weapon" in the standoff.

The officer from Iran's volunteer Basij militia said Iran could block oil traffic through the strategic Strait of Hormuz if the West threatens its economy over Tehran's nuclear programme.

"With Iran's authority over the Strait of Hormuz, the passageway to more than 40 percent of the world's energy, we have become so strong that the world's economic and energy security are in the hands of Iran," deputy Basij commander General Majid Mir Ahmadi was quoted as saying by the semi-official Fars news agency.

"We can exert pressure on the US and British economies as much as we ourselves are put under pressure," he said.

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