Iran's president on Wednesday proposed a debate with U.S. President George W. Bush at this month's U.N. General Assembly, saying it would be the perfect place for an uncensored discussion the whole world could watch.

The White House had no immediate response. But it dismissed a previous TV debate proposal from President Mahmoud Ahmadinejad as a "diversion" from serious concerns over Iran's nuclear program.

CountryWatch: Iran

It was not clear if Iran planned to make a formal proposal through diplomatic channels or whether — as seemed more likely — the president's comments were merely another in a line of provocative and often confrontational statements he has made since taking office a year ago.

The overture did seem to signal that Ahmadinejad is determined to try to shape the world debate over Iran's intentions and continue to ignore the West's insistence to curb its nuclear program.

Iran on Wednesday also postponed a tentative meeting with a top European Union official to discuss the nuclear controversy — a step that seemed to dim prospects the country will make concessions. The United States has said it will push for U.N. sanctions because of Iran's refusal to suspend uranium enrichment as the U.N. had demanded.

Iran insists its nuclear program is for peaceful energy uses only but the United States and some Europeans believe the regime seeks nuclear weapons. On Tuesday, Bush said he would never allow a nuclear-armed Iran because such a government could blackmail the free world.

"I am not going to allow this to happen," Bush said in a speech on terrorism. "And no future American president can allow it, either."

A spokesman for U.N. Secretary General Kofi Annan demurred when asked if the late September world gathering, also known as the General Debate, would be a suitable place for a Bush-Ahmadinejad debate.

The United Nations headquarters has no formal debating facility, though one of its numerous conference rooms could certainly be used.

"I'm just not going to go down this road, I've decided," said Annan spokesman Stephane Dujarric.

Ahmadinejad made the debate proposal at a cabinet meeting in Tehran and it was reported on his official web site. He said the U.N. venue would allow Americans and people around the world to watch and listen without censorship, and that Bush could bring advisers.

"We are ready to discuss the ways of managing the world for achieving justice, peace, friendship and removing violations and threats," he said in the cabinet meeting, according to the Web site.

During an earlier speech Wednesday to a religious conference, the president said he proposed a debate originally "to say that the period of bullying has expired. But false advocators of democracy avoided it because of their arrogance and lack of logic," Ahmadinejad said, according to the Islamic Republic News Agency.

He also issued a veiled threat to Bush at the religious conference, the news agency said, saying that anyone who turned down an invitation was likely to face a bad fate — although the agency did not release his exact quotes.

The nuclear talks had been tentatively set for Wednesday in Vienna as a final attempt to see if there was common ground to start negotiations between Iran and the six nations trying to persuade it to limit its nuclear program.

The European Union's Javier Solana had been ready to fly to the Austrian capital at short notice, but the talks had been left hanging by uncertainty over whether Iranian nuclear envoy Ali Larijani would come.

"We will not have the meeting today in Vienna," Ali Ashgar Soltanieh, the chief Iranian envoy to the International Atomic Energy Agency, told The Associated Press, after Iran postponed the meeting. "Both sides are arranging (a meeting) for a couple of days later."

There was no immediate comment from Solana's office in Brussels. Soltanieh said the decision to postpone any meeting had been mutual, but it appeared that Iranian reluctance had scuttled the chance of talks Wednesday.

In Ankara, Turkey, Annan, whose visit to Tehran last week failed to budge the leadership on its refusal to give up enrichment, urged Iran "to do whatever it can to reassure the international community that indeed its intentions are peaceful."

Russia and China, which are both veto-wielding members of the Security Council and have key trade ties with Tehran, have urged patience with Iran.

Some European nations also remain hesitant to call a halt to three years of talks, with Britain the firmest backer of the U.S. drive for punitive measures.

On Wednesday, Moscow appeared to hold out a possible compromise, saying any U.N. sanctions — if imposed on Iran — would necessarily rule out military action against the country. Iran has long craved just such a security guarantee from the United States, but it was unclear if the United States would agree to any such explicit guarantee, or insist on keeping its options open.

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