Vice President Ali Akbar Salehi, who also heads the Atomic Energy Organization of Iran, reiterated that Iran is in talks with the International Atomic Energy Agency to set a timetable "soon" for an inspection of the site near the holy city of Qom.
The revelations of the site that had been secretly under construction brought increased international pressure on Iran to come clean on its nuclear program, which the U.S. and others suspect is aimed at producing atomic bombs. Salehi's disclosures came two days before the five permanent members of the U.N. Security Council and Germany meet in Geneva with Iran over its nuclear activities.
Salehi said Iran is willing to have a general discussion about nuclear technology when the country sits down with Western powers in Geneva but will not give up its "sovereign right" to uranium enrichment and conversion.
He said the nuclear facility is next to a military compound of the Revolutionary Guard, Iran's most powerful military force, equipped with an air defense system. Salehi also said President Mahmoud Ahmadinejad told him Tuesday he named the enrichment plant "Meshkat," which means Lantern.
"This site is at the base of a mountain and was selected on purpose in a place that would be protected against aerial attack. That's why the site was chosen adjacent to a military site," Salehi told a news conference. "It was intended to safeguard our nuclear facilities and reduce the cost of active defense system. If we had chosen another site, we would have had to set up another aerial defense system."
Details about the newly revealed site and the fact that Iran kept its construction secret have raised more suspicion among experts and Western governments that Iran's nuclear program is aimed at producing weapons - something Tehran has long denied. The U.S. and its allies have strongly condemned Iran over the site and demanded it immediately make a full disclosure on its nuclear activities or face harsher international sanctions.
President Barack Obama's administration is planning to push for new sanctions against Iran, targeting its energy, financial and telecommunications sectors if it does not comply with international demands to come clean about its nuclear program, according to U.S. officials.
Israel, which has attacked nuclear sites in Iraq and Syria previously, considers Iran's nuclear and missile development a strategic threat and Ahmadinejad has made repeated references to Israel's destruction. Israel has not ruled out a pre-emptive military strike on Iranian nuclear facilities.
But Israeli officials have been instructed not to comment on the newly revealed nuclear site or Iran's missile tests on Sunday and Monday.
Salehi said Iran will officially inform the IAEA of details about the site at a later date.
He said the Qom facility was a "contingency" facility to make sure that Iran's nuclear activities won't stop even for a moment.
"This is a contingency plan. It is one of pre-emptive measures aimed at protecting our nuclear technology and human work force. It is a small version of Natanz," he said. "This is to show that the Islamic Republic of Iran won't allow its nuclear activities stop under any circumstances even for a moment."
Natanz is an industrial-scale enrichment plant in central Iran while the Qom facility, according to Salehi, is a semi-industrial facility."
He gave the location of the site as about 60 miles (100 kilometers) south of capital Tehran on the road leading to Qom. That is about 20 miles (30 kilometers) north of Qom. He dismissed a statement by Iran's Foreign Ministry spokesman on Monday that the facility was near the village of Fordo, which is about 30 miles south of Qom.
A satellite image provided by DigitalGlobe and GeoEye shows a well-fortified facility built into a mountain about 20 miles northeast of Qom, with ventilation shafts and a nearby surface-to-air missile site, according to defense consultancy IHS Jane's, which did the analysis of the imagery. The image was taken in September.
GlobalSecurity.org analyzed images from 2005 and January 2009 when the site was in an earlier phase of construction and believes the facility is not underground but was instead cut into a mountain. It is constructed of heavily reinforced concrete and is about the size of a football field - large enough to house 3,000 centrifuges used to refine uranium.
Salehi said the site was selected after a careful study by the authorities. He said it was a formerly an ammunition depot before his agency took control of it a year ago and started construction that will eventually house a uranium enrichment plant.
He said the only connection between the Qom nuclear facility and the Guard is the Guard would protect it against possible attacks.