A senior US official told AFP that the images broadcast by US television of the huge Parchin military site revealed what "amount to weapons intent", but the charges were categorically denied by Tehran.

The allegations came as the United States and Europe were failing at a meeting in Vienna of the UN nuclear watchdog the International Atomic Energy Agency (IAEA) to reach agreement on setting a deadline for Iran to clear up suspicions it has a covert nuclear weapons program.

AFP had reported last week that the UN atomic agency was interested in visiting Parchin, 30 kilometres (19 miles) southwest of Tehran and site for a variety of defense projects, including work in chemical explosives.

The US ABC news network released satellite images of Parchin on Wednesday which it said showed a high-explosives test area that could permit testing for development of a nuclear weapon.

A US official had told AFP last week the concern about Parchin was that the Iranians may be working on testing "high-explosive shaped charges with an inert core of depleted uranium" as a sort of dry test for how a bomb with fissile material would work.

A non-American diplomat confirmed the US assertion.

IAEA spokesman Mark Gwozdecky said the agency "was discussing with Iranian authorities open source information relating to dual-use equipment," an apparent reference to high-speed cameras that have civilian applications but can also monitor explosions.

Gwozdecky refused to "comment on specific sites or issues."

Iran, which says its nuclear program is peaceful, Thursday vigorously denied the charges about Parchin. "We categorically deny any nuclear-related testing at Parchin," Hossein Mousavian, head of Iran's IAEA delegation told

Mousavian also denied reports that the IAEA has requested to visit Parchin.

"They did not request to go," he said but "if this is requested by the IAEA, we are fully ready to cooperate."

Diplomats have told AFP, however, that the IAEA has asked to visit Parchin and that the Iranians have not agreed to the visit.

A diplomat close to the IAEA confirmed that the agency had requested to send inspectors to Parchin but said this was not included in an IAEA report on Iran published September 1 since "whenever you are in the negotiating process, you should not mention what you are negotiating.

A gap remained between the two sides at the IAEA meeting that began here Monday and was threatening to drag on into the weekend.

According to the latest US draft of a resolution the two sides are working on, Iran would have to cease all activities related to uranium enrichment by October 31 or face being taken before the UN Security Council for possible sanctions.

The draft, seen by AFP, states that the IAEA believes "it is essential that Iran immediately suspend all enrichment-related activities... and that this be verified by the agency no later than October 31".

The draft said the IAEA would then "make a definitive decision about what further steps are required in relation to Iran's obligation under its NPT (the nuclear Non-Proliferation Treaty) safeguard agreement", a clear reference to going to the Security Council.

But Europe's so-called Big 3 -- Britain, France and Germany -- favor constructive engagement with Iran.

They do not want a resolution to automatically require the IAEA to send the Iranian dossier to the Security Council, even if a deadline is set for Iran to suspend enriching uranium, the key process that makes fuel for civilian reactors but also the explosive cores of atomic bombs.

European diplomats also protest that enrichment is not technically a violation of the nuclear Non-Proliferation Treaty, since the NPT does not ban this activity.

All rights reserved. � 2005 Agence France-Presse. Sections of the information displayed on this page (dispatches, photographs, logos) are protected by intellectual property rights owned by Agence France-Presse. As a consequence, you may not copy, reproduce, modify, transmit, publish, display or in any way commercially exploit any of the content of this section without the prior written consent of Agence France-Presse.