WASHINGTON/VIENNA, 21 November 2004 — The United States defended its charges that Iran was working to fit a missile with a nuclear warhead and dismissed doubts about the reliability of its intelligence on the Islamic republic.

And the No. 2 US diplomat suggested Washington’s deliberately tough line was part of a strategy that could help Europeans who are negotiating to persuade Iran to suspend some nuclear activities.

“We believe we are on very, very solid ground in pointing to a clandestine effort by Iran to develop weapons of mass destruction and their delivery systems,” Adam Ereli, a State Department spokesman, told reporters.

The Washington Post cited unidentified US officials as saying the information, made public by Secretary of State Colin Powell, was unverified and based on a single “walk-in” source. Ereli said he would not discuss intelligence.

Separately, European Union foreign policy chief Javier Solana, a former NATO boss, challenged the US allegations.

Deputy Secretary of State Richard Armitage said the US stance made the Europeans’ negotiations more effective. “My view would be that the incentives of the Europeans only work against the backdrop of the United States being strong and firm on this issue,” Armitage told the Arab-language television network Al-Jazeera. “In the vernacular, it’s kind of a good cop-bad cop arrangement. If it works, we’ll all have been successful.”

A senior State Department official, who asked not to be named, told reporters the intelligence Powell cited on Iran was “good enough to talk about.”

Western diplomats in Vienna also said that despite the European accord, which takes effect Nov. 22, Iran was preparing large amounts of uranium for enrichment, a process that can be used to make nuclear weapons. Iran denied the accusation.

Ereli, who could not substantiate those claims, said, “These allegations only heighten our concerns that Iran continues to pursue nuclear activities and does not honor its commitments.”

It was not clear if this would harm Iran’s drive to convince the UN watchdog International Atomic Energy Agency (IAEA) not to send it to the UN Security Council, which could impose punishing sanctions, for what the United States says is a covert nuclear weapons program.

The United States called on Britain, France and Germany, which had negotiated the enrichment freeze with Tehran, to send a “stern message” to Iran to stop producing the uranium feedstuff gas.

“We told the Europeans that we consider this to be really an act of bad faith and to deliver a stern message to Iran that they must stop this,” an official said.

The US State Department had said earlier in Washington that if reports that Iran was making the uranium hexafluoride (UF6) gas that is the feed used to make enriched uranium proved to be true, it would further erode Tehran’s already shaky credibility in nuclear matters.

Enriched uranium, made by spinning UF6 in what can be cascades of thousands of centrifuges, can be fuel for nuclear reactors or the raw explosive material for atomic bombs. A total of “37 tons of uranium yellowcake ore have been introduced into Iran’s uranium conversion facility in Isfahan and an unknown amount of UF6 has been produced,” a Western diplomat said.

The comments were confirmed by other diplomats close to the IAEA, which has inspectors in Iran ready to verify the suspension of uranium enrichment that Tehran has said will begin tomorrow.

Henry Sokolski, head of the Washington think tank the Nonproliferation Policy Education Center, said the Iranians were technically within their rights to make the uranium gas since the suspension starts tomorrow. “This is humiliating to the Europeans but it’s legal. What it shows is that the Iranians can run circles around the European negotiators,” Sokolski said.