President Ahmadinejad announced yesterday that Iran had defied the United Nations and started “industrial-scale” production of enriched uranium. He promised to defend the nuclear programme “to the end” as school bells rang out in celebration of a “national day of nuclear energy”. The Government also sent millions of text messages congratulating its citizens.

In Tehran, about 200 students formed a human chain at the Atomic Energy Organisation while chanting “death to America” and “death to Britain”. They later burnt the flags of both countries. The scenes drew swift condemnation from Washington where Sean McCormack, the State Department spokesman, said neither the UN Security Council nor the international nuclear watchdog “believe Iran’s assurances that their programme is peaceful in nature”.

He added: “What we are looking for are reasonable Iranian [leaders to] see that it is not to the benefit of the Iranian people to continue to pursue the course on which they find themselves.”

President Ahmadinejad’s comments, 12 months to the day since Iran succeeded in enriching uranium and 27 years since it severed diplomatic relations with the US, included threatening language designed to stir nationalist sentiment.

“Our nation has until this day moved on a peaceful path, observing laws created by the world powers, and it is interested in continuing along this path,” he said. “But they should take care not to do something that makes Iran reconsider its behaviour, as the Iranian nation is capable of doing so. We recommend to them that they had better respect nations’ rights.”

Speaking at the enrichment plant in Natanz, President Ahmadinejad said: “The great Iranian nation, which for past centuries has been a pioneer of science, will not allow some bullying powers to put obstacles in its path of progress by influencing the international community. We will go on to reach the summits, today. . . this country has joined the countries that produce nuclear fuel on an industrial scale.”

In the enrichment process, uranium gas is pumped into a “cascade” of thousands of centrifuges, which spin the gas at supersonic speeds to purify it. Uranium enriched to low levels of 3 per cent or more can be used as fuel, while a far higher level — above 90 per cent — is needed for a weapon.

Ali Larijani, the chief negotiator on the issue, claimed that his country had begun injecting uranium gas into 3,000 centrifuges for enrichment. Previously Iran had been known to have only 328.

The International Atomic Energy Agency, the UN nuclear watchdog, had no immediate comment, but Germany’s Foreign Ministry, which currently holds the EU presidency, said that the move showed Iran was “definitively going in the wrong direction”. The UN Security Council imposed limited sanctions against Iran in December, which were strengthened slightly last month to include travel bans against named individuals.

But Iranian state television reported yesterday that a Revolutionary Guard general supposedly under such restrictions had visited Russia — a permanent member of the Security Council — without difficulty.

General Mohammad Baqer Zolqadr said that his six-day journey to Moscow showed “the ineffectiveness of the [Security Council] resolution.” Andrei Krivtsov, a Russian foreign ministry spokesman, confirmed that General Zolqadr had visited. He said that the resolution did not prohibit visits by the listed individuals, but called for heightened vigilance “directed first of all at people who are directly related to nuclear programmes” — suggesting that General Zolqadr was not.

A Foreign Office source suggested that President Ahmadinejad’s comments may have been directed primarily at hardline domestic critics of the Government’s decision to release the detained British Service personnel.

“He can’t allow himself to appear as if he is going soft,” said the source.

“We are a little bit sceptical about whether that they have got as far as he is claiming.”

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