"We will pursue this case with the agency and the date of the visit will be announced after we reach an agreement with the IAEA."
He said the new plant was on the road between Tehran and the holy city of Qom -- the first official disclosure of its location.
"It is 100 kilometres (60 miles) far from Tehran and more details will be given about the site later to the Iranian people," he added.
On Friday, the IAEA said Tehran wrote to the agency on September 21 disclosing that it is building a new uranium enrichment facility.
"God willing this new plant will become operational soon and make the enemy blind," Mohammad Mohammadi Golpayegani, supreme leader Ayatollah Ali Khamenei's chief of staff, was quoted by Fars news agency as saying on Saturday.
He did not give any time frame.
The announcement of the new facility came just days before an October 1 meeting in Geneva between Iran and six world powers to discuss Tehran's disputed atomic programme.
Ahmadinejad denied Tehran was building the plant in secret, as charged by Western leaders, and told reporters in New York on Friday the facility was "completely legal."
"We actually informed the agency (IAEA) 18 months ahead of time. Is this the right thing to do or the wrong thing to do? I thought we are supposed to be encouraged for taking this action."
Salehi said building the plant was a "guarantee" that Tehran's nuclear work would continue.
"Considering the threats (to existing nuclear sites), our organisation decided to do what is necessary to preserve and continue our nuclear activities," he told state television.
"So we decided to build new installations which will guarantee the continuation of our nuclear activities which will never stop at any cost."
Obama and other Western leaders have threatened Tehran with new sanctions if it does not come clean during the Geneva talks between Iran's top nuclear negotiator Saeed Jalili and representatives of Britain, France, Russia, China, Germany and the United States.
The six world powers suspect Tehran is developing atomic weapons under the guise of a civilian nuclear energy programme, a charge Iran vociferously denies.
Uranium enrichment lies at the heart of the nuclear controversy, since the process can be used to make an atomic bomb as well as producing fuel for nuclear reactors.
Iran has refused to suspend enrichment, and government-run daily Iran on Saturday trumpeted the announcement of the new plant with the headline: "A new victorious step taken in the nuclear domain."
Tehran's new facility "is a serious challenge to the global non-proliferation regime, and continues a disturbing pattern of Iranian evasion," Obama said in his weekly audio and video address on Saturday.
"But Iran must now cooperate fully with the International Atomic Energy Agency, and take action to demonstrate its peaceful intentions."
Obama said "the international community is more united than ever before."
Iran's leaders "must now choose -- they can live up to their responsibilities and achieve integration with the community of nations. Or they will face increased pressure and isolation, and deny opportunity to their own people."
On Friday he did not rule out a military option to halt Tehran's galloping nuclear drive.
On Saturday, Iran's arch-foe Israel called for an "unequivocal" response from the West at Geneva.
"We are not surprised by the recent revelations, because we have been saying that Iran is developing its nuclear activities for military purposes, and the facts prove it now," Israeli Foreign Minister Avigdor Lieberman told public radio.
French President Nicolas Sarkozy, in a joint appearance with Obama and British Prime Minister Gordon Brown at the G20 summit in Pittsburgh on Friday, threatened rapid sanctions against Iran.
"In December, if there is not an in-depth change in Iranian leaders, sanctions will have to be taken," he said.
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