But speaking at a meeting of EU foreign ministers, he played down the prospects of any EU initiative soon, and dismissed a report that the United States might take military action in the nuclear standoff with Tehran.

"We have to be prepared just in case they fail," he said, referring to diplomatic efforts to persuade the Islamic republic to renounce sensitive atomic activities, currently centred on the UN Security Council.

"We have to begin thinking about that possibility," he said, referring to the chances of eventual sanctions. Asked specifically about a visa ban, he said that such a move "is a classical type of measure that is taken."

His comments came as Iranian President Mahmoud Ahmadinejad vowed he would not back down "one iota" over Iran's nuclear programme, again rejecting a UN Security Council demand for Tehran to freeze sensitive enrichment work.

"Our enemies know they are unable to even slightly hurt our nation and they cannot create the tiniest obstacle on its glorious and progressive way," the hardline Iranian leader said in a speech in the northeastern city of Mashhad.

British Foreign Secretary Jack Straw underlined that the threat of sanctions is for the moment an issue for the UN Security Council, which, he noted, has given Tehran 30 days to reconsider its position.

"We hope very much that this matter can be resolved both by diplomatic means and also without the need for sanctions," he said.

He admitted however that the EU was considering the issue -- including by means of a discussion paper presented by Solana to Monday's meeting in Luxembourg.

"We're looking at the issue, but entirely on a contingency basis. What we want, what the European Union wants .. is to try to resolve this issue by diplomatic means," he said.

Solana dismissed a report that US President George W. Bush is mulling military options to knock out Iran's nuclear program.

The New Yorker magazine has reported that the administration is planning a massive bombing campaign against Iran, including use of bunker-buster nuclear bombs to destroy a key suspected Iranian nuclear weapons facility.

"I have read the article ... I think it has nothing to do with reality," he said, although admitting: "I don't know what is going on in the Pentagon and the different levels of the Pentagon."

However, Solana said: "Any military action is absolutely out of the table for us."

Straw reiterated that the EU was not questioning Iran's right to civil nuclear technology.

"That is not the issue. The issue is the years of deception, deceit by Iran," he said, noting the "serious concerns in the international community about how they may misuse their fuel cycle for nuclear weapons purposes."

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