Javier Solana, the European Union foreign policy chief, is due in Tehran on Monday to deliver details of an international incentive package of ?carrots and sticks? aimed at resolving the nuclear dispute.
Iran?s supreme leader on Sunday warned that energy supplies from the Gulf would be disrupted if the US made a ?mistake? against his country,.
In an attempt to raise the diplomatic stakes and deflect growing international pressure, Ayatollah Ali Khamenei, the ultimate decision-maker, appeared to contradict earlier assurances from Tehran that the world?s fourth largest oil producer would not use the oil weapon.
?If Americans make a mistake about Iran, the flow of energy from this region will definitely be jeopardised,? he said in a speech, insisting, however, that Iran would never be the initiator of war. His comments are likely to unsettle oil markets when they open on Monday.
Iranian analysts say the regime considers one of its most potent cards the ability to disrupt energy supplies through the straits of Hormuz, from which much of the world?s oil shipments pass.
But Condoleezza Rice, the US secretary of state, on Sunday played down the leader?s threats, highlighting that Iran depended heavily on oil revenues.
Mr Khamenei did not specifically mention last week?s US offer of talks with Iran if it agreed to suspend uranium enrichment and processing activities. But he referred scathingly to a ?recent message from Americans?, describing it as ?rude, cheap and full of foolish arrogance?.
Sticking to Iran?s official position that it has no intention of building a nuclear bomb, he suggested the regime felt emboldened and saw no need to make concessions at this time. He said the government in Tehran was ?one of the most popular in the last 100 years since the constitutional revolution?, while the Bush administration was ?one of the most hated governments in the history of the US?.
Despite an agreement reached last Thursday by the US, UK, France, Russia, China and Germany, to offer Tehran a package of incentives in return for suspending uranium enrichment ? or move to impose penalties at the UN Security Council ? Mr Khamenei insisted that there was no international consensus on Iran policy.
Yet the bold rhetoric combined with milder messages from other senior officials, including the fundamentalist President Mahmoud Ahmadi-Nejad. After speaking with Kofi Annan, the UN secretary-general, Mr Ahmadi-Nejad said on Saturday Iran would study the international proposals and not rush to judgment.
Analysts in Tehran said the occasion of Mr Khamenei?s speech marking the anniversary of the death of Ayatollah Ruhollah Khomeini, founder of the Islamic Republic, required the projection of a defiant image.
But the leader?s comments also highlighted the challenge ahead for the world community in trying to persuade the regime to give up uranium enrichment. ?The leader wants to show that Iran can stand firm and that it won?t falter,? said one analyst. ?At the same time. Iran will study the proposals and postpone any decision on them as long as possible.?
Mr Khamenei dismissed the promise of fuel supplies to Iran?s nuclear plants from abroad, which is said to be part of the international offer. No ?honest? official, he said, would agree to forgo nuclear technology and beg western nations for energy.
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