Israel warned the Obama administration this week that the window of opportunity for dealing diplomatically with the Iranian nuclear threat has closed.

At the Israeli cabinet meeting on Sunday, Major General Amos Yadlin, commander of the IDF’s Intelligence Branch, said: “Iran has crossed the technological threshold. It is one strategic decision away from becoming a nuclear-enabled military power.” He indicated that Iran can now build a bomb in a matter of months.

In an unusual move, General Yadlin’s assessment to the cabinet was made public. He added that “Iran is continuing to stockpile hundreds of kilograms of low-grade enriched uranium.”

Gen Yadlin’s statement is being seen as a wake-up call to the United States.

There is a consensus within the Israeli intelligence services that diplomatic and other efforts to hinder Iran have been ineffectual and that further dialogue — the strategy favoured by President Barack Obama — will only hand the Iranians more time.

Last week, the Chairman of the Joint Chiefs of Staff, Admiral Mike Mullen, said that the Iranians already had sufficient nuclear material to build a bomb, and Secretary of State Hillary Clinton said that she was sceptical that the Iranians would respond positively to the American diplomatic initiative.

However, Defence Secretary Robert Gates said he did not believe that the Iranians were close to building a nuclear bomb.

President Obama has yet to announce a clear decision regarding Iran.

The International Atomic Energy Agency reported last month that Iran had already enriched over 1,000kg of uranium at a low-level, enough for one nuclear warhead.