VIENNA (Reuters) - Iran's nuclear envoy said on Friday it would be a "strategic mistake" to build atom bombs, dismissing what a leading Western expert cited as evidence suggesting Tehran was seeking the means to do just that.
Ali Asghar Soltanieh, Iran's ambassador to the International Atomic Energy Agency (IAEA), also insisted during a public debate that sanctions and the Stuxnet computer virus had failed to slow the Islamic Republic's disputed nuclear program.
"Please be assured that none of the sanctions have affected our nuclear activities ... 100 percent sure," he said.
Asked about Stuxnet, which Iran has blamed on enemies waging a "cyber war" against it, he said: "No destruction, no problem."
Western analysts say increasingly tough sanctions on Iran as well as Stuxnet and possible other sabotage have delayed Iran's nuclear progress, even though they say the country now has enough low-enriched uranium for two bombs if refined more.
Enriched uranium can be used to fuel power plants, Iran's stated aim, or provide bomb material if processed much further.
Any setbacks for Iran's nuclear work could buy more time for major powers to try and reach a diplomatic solution. Israel and the United States have refused to rule out military action to prevent Iran from acquiring nuclear bombs.
Soltanieh said that developing nuclear bombs would put Iran at a disadvantage in any talks with the United States and other nuclear-armed states, which would have many more such weapons.
"Because the United States (would say): 'Wait a minute, you only have 2-3 weapons, I have thousands, I'm very powerful'."
Soltanieh added: "We don't want to make this strategic mistake. Without nuclear weapons we are as strong and powerful as the nuclear weapons states."
Mark Fitzpatrick, a senior fellow for non-proliferation at the International Institute for Strategic Studies think tank, said "the totality of the evidence indicates beyond reasonable doubt" that Iran was seeking a capability to make such weapons.
NUCLEAR BOMB TRIGGER?
If Iran decided to "weaponise" enrichment, it would need about 16 months to yield the first bomb's worth of highly enriched uranium at its Natanz enrichment facility, if all centrifuge machines were used for this purpose, he told the seminar.
At least six months would then be required to fashion the highly-refined uranium into a weapon, Fitzpatrick added. Developing a missile to deliver it would add to the timeline, the former senior U.S. State Department official said.
But one bomb would be insufficient as a credible deterrent.
"It would seem foolhardy for a nation to go for broke, with the international reaction that would entail, before it could manufacture at least a handful of weapons," Fitzpatrick said.
"Assembling such an arsenal would multiply both the amount of weapons-grade uranium that would be needed and the amount of time it would take Iran to reach the threshold capability."
An IAEA report this week said it had received new information about possible illicit military dimensions to Iran's nuclear activities
"The latest IAEA report includes evidence that what originally were thought to be just paper studies also include actual experiments, including on triggers for a nuclear weapon," Fitzpatrick said.
Meetings in December and January between Iran and the six world powers failed to break the deadlock in the nuclear row.
Soltanieh said Iran was ready to hold talks about "all global and regional issues," as well as nuclear proliferation and disarmament issues in general -- comments unlikely to please Western officials who want to keep the focus squarely on Iran.
"Of course the others could have the freedom to raise questions about us," Soltanieh said. "We are very pragmatic and very constructive."
(Editing by Mark Heinrich)