Bangkok Post

France said Iran's refusal to allow the inspectors to see a key military site used for suspected atomic weapons research was a ``missed opportunity'' that could undermine chances of reviving wider talks between Tehran and world powers.

Iran's supreme leader, Ayatollah Ali Khamenei, was defiant, however.

He made no mention at all of the failed bid by the International Atomic Energy Agency inspectors. Instead he reiterated the assertion that ``the Iranian nation has never been seeking an atomic weapon and never will be.''

Possessing a nuclear bomb, he said, ``constitutes a major sin,'' he told a group of nuclear scientists.

Khamenei added: ``Pressure, sanctions, threats and assassinations will not bear any fruit and Iran will continue its path of (nuclear) scientific development.''

The IAEA said it had gone into the two-day visit to Tehran _ and a previous, inconclusive one last month _ in a ``constructive spirit,'' but that no agreement had been reached on efforts to elucidate Iran's nuclear activities.

Despite requests, ``we could not get access'' to Iran's military site in Parchin where suspected nuclear warhead design experiments were conducted, the leader of the IAEA team, chief UN inspector Herman Nackaerts, said on his return to Vienna.

IAEA chief Yukiya Amano said the Iranian's refusal to allow the Parchin inspection was ``disappointing.''

The IAEA said that ``at this point in time'' there was no agreement with Iran on holding further talks.

A Western diplomat in Vienna said that Iran's decision on Parchin showed why the international community ``lacks confidence in the nature of its nuclear programme.''

``This latest snub, along with its decision to begin enrichment at Qom, underscore Iran's defiance of the international community and multiple Security Council resolutions,'' said the diplomat.

The IAEA trip was seen as having an impact on the mooted resumption of talks between Iran and the P5+1 powers _ Britain, China, France, Russia and the United States, plus Germany _ which broke down 13 months ago.

France said Iran's ``refusal to cooperate'' was ``another missed opportunity'' that added to a standoff already aggravated by the Islamic republic's recent boasts of nuclear progress.

``We cannot but consider all of this contrary to the intentions'' declared by Iran to resume negotiations with the P5+1, said a spokesman.

Oliver Thraenert, an analyst with the German Institute for International and Security Affairs, said the IAEA visit ``shows clearly that Iran is not in the mood for substantial compromise.''

``The chances now of a return to negotiations between Iran and the P5+1 are not very high. It leaves matters in a deadlock.''

Already talk of possible military action against Iran by Israel, with or without US help, had been giving urgency to diplomatic attempts to lower tensions.

Russia, which along with China has been giving Iran diplomatic cover, warned against that prospect.

``The scenario of military action against Iran would be catastrophic for the region and possibly the whole system of international relations,'' said Deputy Foreign Minister Gennady Gatilov.

He urged nations to wait for the IAEA's official report before deciding to condemn Iran for failing to cooperate.

The United States and Europe have been ramping up economic sanctions on Iran since November, when the IAEA published a report crystallising _ though not entirely validating _ Western suspicions it was pursuing nuclear weapons research in Parchin and elsewhere.

The measures, targeting vital oil exports, added to four sets of non-economic UN sanctions punishing Iran for not giving timely explanations of its activities.

Iran has repeatedly said the sanctions will not deter it from its nuclear ambitions, and it has threatened to strike back at any military action, possibly by closing the strategic Strait of Hormuz.

This week, it deployed warplanes, missiles and radar facilities in exercises to boost the defences of its nuclear facilities.

Iran ``does not seek war and has never started a war, but it will vigorously defend its national interests,'' Defence Minister Ahmad Vahidi said.

Iran has also announced a halt to the limited amount of oil it exported to Britain and France in retaliation for an EU embargo on its oil due to come fully into effect in July.

On Tuesday, the government threatened to cut supplies to other EU nations if they did not stop their ``hostile'' policies.