Tehran, Iran (CNN) -- Iran's top atomic energy official has denied the existence of a major top-secret nuclear enrichment site near Tehran.
"We have no such installation where we enrich uranium," said Ali Akbar Salehi, who spoke to the semi-official Mehr News Agency on Friday.
Supporters of an Iranian opposition group announced Thursday that they have "exclusive" details on a major top-secret strategic nuclear enrichment site buried deep in a mountain northwest of Tehran. But U.S. government officials and nuclear experts are not convinced over the claim.
Alireza Jafarzadeh, speaking for the National Council of Resistance for Iran, said its members obtained the information from Iran's chief opposition group, the People's Mujahedeen Organization of Iran, which was credited with exposing Iran's first nuclear site in Natanz in 2002. The PMOI is currently listed by the State Department as a designated terrorist organization.
"This has no peaceful intentions whatsoever," Jafarzadeh said at a news conference Thursday. This comes amid Western concerns that Iran intends to develop nuclear weapons.
Salehi said Friday that if they "really are aware of such an installation, perhaps they would like to tell us about it so that we can thank them."
"No such nuclear installation with a specific definition exists in Iran which has not been declared to the agency," he said, referring to the International Atomic Energy Agency, the U.N.'s nuclear watchdog.
"Facilities which are used for medical and agriculture purposes are not considered nuclear. There are many such facilities in Iran," Mehr quoted Salehi as saying.
But Jafarzadeh said the site is controlled and operated by the minister of defense, hidden from the International Atomic Energy Agency and the outside world.
According to another Mehr report, Iran also announced a development Saturday regarding its Bushehr plant. Salehi is quoted as saying that nuclear fuel will be loaded into the core of the Bushehr reactor at the beginning of the Iranian calendar month of Mehr, around September 23.
He said the plant then will be able to produce electricity in the Iranian calendar month of Azar, which is November 22 to December 21.
This comes after the plant was launched on August 21 when engineers loaded 163 fuel rods into the reactor under the supervision of the IAEA.
The plant will produce 1000 megawatts of electricity once all the fuel rods are loaded into the core of the reactor, the Mehr report said.
Citing a report from a nuclear group, Mehr reported that the Bushehr plant may save Iran 11 million barrels of crude oil or 1.8 billion cubic meters of gas per year.
CNN's Mitra Mobasherat contributed to this report.