"Foreign tourists can visit Iranian nuclear sites, after an order from President Ahmadinejad," Esfandyar Rahim Mashaii, head of Iran's Tourism and Cultural Heritage Organization, was quoted as saying by the state television.

The president gave this order to prove Iran's nuclear program had been peaceful, and it was aimed at generating electricity, notnuclear bomb, said Mashaii.

"We are reviewing the related instructions in this regard," he added.

No immediate details were reported on the definition of a foreign tourist and when it could be legally implemented, but possible nuclear sites include Iran's first nuclear plant being built in the southern city of Bushehr, the uranium conversion facility near Isfahan and the uranium enrichment plant in Natanz.

Before the authorization, only inspectors from the International Atomic Energy Agency (IAEA) and some reporters were allowed to enter these mysterious nuclear sites.

The United States has accused the Islamic Republic of using the nuclear energy program as a cover to develop atomic weapons and pushed UN Security Council for possible sanctions on the country.

But Iran has rejected the accusations, insisting that its nuclear program was totally peaceful.