Tehran, Iran ? Iran intends to enrich uranium on a scale hundreds of times larger than its current level, the country’s deputy nuclear chief said Wednesday, signaling its resolve to expand a program the international community insists it halt.

President Mahmoud Ahmadinejad said Tuesday that Iran for the first time had succeeded on a small scale in enriching uranium, a key step in generating fuel for a reactor or fissile material for a bomb. The U.N. Security Council has demanded that Iran stop all enrichment activity because of suspicions the program’s aim is to make weapons.

Iran’s small-scale enrichment used 164 centrifuges, which spin uranium gas to increase its proportion of the isotope needed for the nuclear fission at the heart of a nuclear reactor or a bomb.

Deputy Nuclear Chief Mohammad Saeedi said Iran has informed the International Atomic Energy Agency that it plans to install 3,000 centrifuges at its facility in the central town of Natanz by late 2006, then expand to 54,000 centrifuges, though he did not say when.

“We will expand uranium enrichment to industrial scale at Natanz,” Saeedi told state-run television.

Saeedi said using 54,000 centrifuges will be able to produce enough enriched uranium to provide fuel for a 1,000-megawatt nuclear power plant like one Russia is finishing in southern Iran.

IAEA head Mohamed ElBaradei arrived in Tehran on Wednesday night to talks aimed at defusing tension over Iran’s nuclear program.

“The time is right for a political solution and the way is negotiations,” ElBaradei told journalists at the airport.

At the United Nations, China called on Tehran to suspend enrichment, but China and Russia reiterated their opposition to any punitive measures against Iran.

The IAEA is due to report to the Security Council on April 28 whether Iran has met its demand for a full halt to uranium enrichment. If Tehran has not complied, the council will consider the next step. The U.S. and Europe are pressing for sanctions, a step that Russia and China have so far opposed.

Iran’s announcement quickly drew condemnations.

Russia criticized the announcement Wednesday, with Foreign Ministry spokesman Mikhail Kamynin saying, “We believe that this step is wrong. “

Russian Foreign Minister Sergey Lavrov reiterated Moscow’s firm opposition to any military action against Iran.

Denouncing Iran’s successful enrichment of uranium as unacceptable to the international community, Secretary of State Condoleezza Rice said the U.N. Security Council must consider “strong steps” to induce Tehran to change course.

Rice also telephoned ElBaradei to ask him to reinforce demands that Iran comply with its nonproliferation requirements when he holds talks in Tehran on Friday.

“This is not a question of Iran’s right to civil nuclear power,” she said. “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.”