Rafsanjani also issued a stern warning to Israel, insisting the Jewish state would not dare to attack the Iran which has "longer arms".

"We are not seeking a confrontation but, if it is imposed on us, we are prepared for it," he told a press conference at the end of a three-day visit to Kuwait.

"The consequences of such an attack on Iran will be very grave and they (the Americans) will not benefit from it."

Rafsanjani, who earlier held talks with Emir Sheikh Sabah al-Ahmad al-Sabah, said Kuwait and other Gulf Arab states had told him they would not back a US attack on Iran.

Rafsanjani, who lost out in elections last year to hardline President Mahmoud Ahmadinejad, remains powerful as the head of the Expediency Council, Iran's top political arbitration body.

His visit to Kuwait followed Iran's announcement last week that it had successfully enriched uranium to the level needed to make reactor fuel, triggering global concern about its nuclear ambitions.

The enrichment process can be extended to make the fissile core of an atom bomb and the UN Security Council has given Iran's hardline leadership until the end of the month to freeze the sensitive fuel cycle work.