President Bush last week said military action against Iran's nuclear programme had not been ruled out and Vice President Dick Cheney said Iran topped the list of world trouble spots and Israel could decide to bomb its nuclear facilities.

But Iran's Foreign Ministry spokesman Hamid Reza Asefi said: "We think the chance (of a US military attack) is very low unless someone wants to make a major strategic mistake."

"Logically speaking, we don't think this is going to happen," he told a weekly news conference.

Iranian officials, including President Mohammad Khatami, said last week Iran would respond vigorously to any attack.

Analysts have said Tehran has ballistic missiles capable of striking Israel or US bases in the Gulf and can easily stir up violence in Iraq, Afghanistan and Palestine through proxy agents and militant groups it backs.