Amidst a report that US commandos had entered Iran to search for sites used for development of nuclear weapons, President George W Bush [Images] said he would not rule out military action against the country, as it had not revealed details of its nuclear programme.

"I hope we can solve it diplomatically, but I will never take any option off the table," Bush told NBC News on Monday night when asked if he would rule out military action against Iran "if it continues to stonewall the international community about the existence of its nuclear weapons programme".

Investigative journalist Seymour Hersh had written the report, which appeared in the New Yorker magazine.

The report also stated that Pakistani scientists were giving information on Iranian nuclear sites to the US.

On Monday, Pentagon [Images] spokesman Lawrence DiRita said the report "is so riddled with errors of fundamental fact that the credibility of his entire piece is destroyed".

"The Iranian regime's apparent nuclear ambitions and its demonstrated support for terrorist organisations is a global challenge that deserves much more serious treatment than Seymour Hersh's report 'The Coming Wars'," DiRita said.

However, the spokesman did not confirm Hersh's claim that the administration had authorised covert operations against 10 Asian countries, including Iran.