The head of the U.N. nuclear watchdog, Mohamed ElBaradei, expressed optimism about his visit to Iran on arriving there for talks aimed at defusing tension over Tehran's nuclear program.

Mohamed ElBaradei, head of the International Atomic Energy Agency, arrived in Tehran, Iran Wednesday, April 12, 2006 to begin talks about Iran's nuclear enrichment program. [AP]

"The time is right for a political solution and the way is negotiations," the head of the International Atomic Energy Agency told journalists at Mehrabad International Airport in Tehran just after midnight Wednesday local time.

ElBaradei's visit began not long after Tehran's announcement Tuesday that the country had successfully enriched uranium, a key step to producing peaceful nuclear energy or nuclear weapons.

"I would like to see Iran come to terms with the requests of the international community," he said, explaining the purpose of his trip as being "to clarify remaining outstanding issues on the nature of the Iranian program."

Earlier Wednesday, the country's deputy nuclear chief said Iran intends to move toward large-scale uranium enrichment involving 54,000 centrifuges, signaling its resolve to expand a program the international community has insisted it halt.

That will be hundreds of times more than what the country has now, reports CBS News correspondent Jim Axelrod. If true, Axelrod adds, that would be enough to produce hundreds of nuclear warheads.

Iran's president had announced Tuesday that the country had succeeded in enriching uranium on a small scale for the first time, using 164 centrifuges. The U.N. Security Council has demanded that Iran stop all enrichment activity because of suspicions the program's aim is to make nuclear weapons.

"We will expand uranium enrichment to industrial scale at Natanz," Deputy Nuclear Chief Mohammad Saeedi told state-run television Wednesday.

He said Iran has informed the International Atomic Energy Agency that it plans to install 3,000 centrifuges at Natanz by late 2006, then expand to 54,000 centrifuges, though he did not say when.

He said using 54,000 centrifuges will be able to produce enough enriched uranium to provide fuel for a 1,000-megawat nuclear power plant like the one Russia is currently putting the finishing touches on in southern Iran.

Iran's claims brought it fresh international condemnation as allies Russia and China joined several European countries and the United States in expressing their disapproval over the nuclear activities.

Already the U.N. Security Council had given it until April 28 to clear up suspicions that it wants to become a nuclear power. It has asked Tehran to suspend enrichment and allow unannounced IAEA inspections.

The White House is pressing for U.N. sanctions against Iran.

ElBaradei said he hoped the visit would ¡°bring Iran in line with the requests of the international community to take confidence-building measures regarding its activities including suspension of enrichment and related activities until outstanding issues are clarified.''

A team of five IAEA inspectors arrived in Iran late last week.

On Thursday, ElBaradei is expected to meet Iran's nuclear chief Vice President Gholamreza Aghazadeh.

"I don't know anyone on god's green earth that actually thinks that's what the Iranians are interested in," Richard Haass, president of the Council on Foreign Relations told CBS News' The Early Show co-anchor Hannah Storm. "They don't need nuclear power for electricity because they've got all this oil and gas. So this is a serious moment. But, again, the world still has time for diplomacy to try to put a ceiling on what they're doing," Haass said.

Iranian President Mahmoud Ahmadinejad announced the enrichment success Tuesday in a nationally televised ceremony, saying the country's nuclear ambitions are peaceful and warning the West that trying to force Iran to abandon enrichment would "cause an everlasting hatred in the hearts of Iranians."

The United States is not taking Iran's claim at face value, CBS News senior White House correspondent Bill Plante reports, and top officials tell CBS News that they just can't be sure. But the announcement quickly raised condemnations from the U.S., who said the claims "show that Iran is moving in the wrong direction."

Denouncing Iran's successful enrichment of uranium as unacceptable to the international community, Secretary of State Condoleezza Rice said Wednesday the U.N. Security Council must consider "strong steps" to induce Tehran to change course. She said "this latest announcement...will further isolate Iran."

Rice also telephoned Mohamed ElBaradei, the head of the International Atomic Energy Agency, to ask him to reinforce demands that Iran comply with its nonproliferation requirements when he holds talks in Tehran on Friday.

The U.S. remains convinced Iran wants to build a nuclear weapon.

"This is not a question of Iran's right to civil nuclear power," Rice said while greeting President Teodoro Obiang Nguema Moasogo of Equatorial Guinea. "This is a question of, ... the world does not believe that Iran should have the capability and the technology that could lead to a nuclear weapon."

Russia also criticized the announcement Wednesday, with Foreign Ministry spokesman Mikhail Kamynin saying, "We believe that this step is wrong. It runs counter to decisions of the IAEA and resolutions of the U.N. Security Council."

Former Iranian president Hashemi Rafsanjani, a powerful figure in the country's clerical regime, warned that pressuring Iran over enrichment "might not have good consequences for the area and the world."

If the West wants "to solve issues in good faith, that could be easily possible, and if they want to ... pressure us on our nuclear activities, things will become difficult and thorny for all," Rafsanjani said in an interview with the Kuwaiti newspaper Al-Rai Al-Aam, published on Wednesday.

Rafsanjani, who heads Iran's Expediency Council, a powerful body that arbitrates between the parliament and the clerical hierarchy, said planned talks between Iran and the United States on stabilizing Iraq could lead to discussions on the nuclear dispute.

"We don't have a mandate to discuss the nuclear issue with the Americans ... but if the talks on Iraq go in the right direction, there might be a possibility for that issue," Rafsanjani said in an interview with the Al-Hayat daily. "There have been many cases where big and wide-ranging decisions had small beginnings."

Iranian and U.S. officials have insisted the talks will deal only with Iraq. So far, no date for the talks has been set.

Enrichment is a key process that can produce either fuel for a reactor or the material needed for a nuclear reactor. But thousands of centrifuges, arranged in a network called a "cascade," are needed for either purpose, and getting any number of centrifuges to work together is a very delicate and difficult task.