U.S. Critical As Iran Marks Nuke Step

White House Calls Iran's Announcement That It Has Enriched Uranium 'Defiant'

(CBS/AP)  The White House on Tuesday criticized the Iranian government after its president said Tehran had successfully enriched uranium for the first time, a potential step toward developing nuclear weapons.

"Defiant statements and actions only further isolate the regime from the rest of the world," White House press secretary Scott McClellan told reporters aboard Air Force One while flying to Missouri.

In a nationally televised speech, President Mahmoud Ahmadinejad announced the development but said his country did not plan to develop nuclear weapons. He asked the West not to try to force Iran to abandon uranium enrichment.

That's exactly what the United States hopes to do — work with allies to curb Iran's nuclear ambitions.

"This is a regime that needs to be building confidence with the international community," McClellan said. "Instead, they're moving in the wrong direction. This is a regime that has a long history of hiding its nuclear activities from the international community, and refusing to comply with its international obligations."

The announcement comes after recent reports that the Bush administration is planning strikes on Iran's nuclear plants, CBS News correspondent Jim Axelrod reports. But at the Pentagon, Secretary of Defense Donald H. Rumsfeld said he would not engage in "fantasyland" speculation about a possible U.S. attack on Iran, though he said the Bush administration is concerned about Tehran's nuclear ambitions.

"The United States of America is on a diplomatic track," Rumsfeld said.

But if Iran's claims are true, then its moving much quicker than initially thought, Axelrod reports. Iran could be just a few years away from having the ability to make a nuclear weapon.

State Department spokesman Sean McCormack said he could not verify what he called the technical details of Tehran's announcement.

"This is another step by the Iranians in defiance of the international community. Once again they have chosen the pathway of defiance instead of the pathway of cooperation," he said.

The Pentagon is reviewing a variety of contingency plans, CBS News' Claudia Coffey reports.

"Everyone agrees that Iran cannot be allowed to possess nuclear weapons. That would be destabilizing for the region as well as the world," McCormack said.

On Monday, Bush said force is not necessarily required to stop Iran from having a nuclear weapon. The president dismissed reports of U.S. plans for a military attack against Tehran as "wild speculation."

The United States is trying to persuade other members of the United Nations Security Council to side with the U.S. and levy sanctions against Iran unless Tehran backs down. Iran's defiant statements have effectively ratcheted up the pressure, CBS News foreign affairs analyst Pamela Falk said.

"Enrichment is a technology benchmark for development of nuclear weapons," Falk said. "This is likely to keep the world powers unified in their effort to stop Iran but it does not mean Iran will produce weapons anytime soon."

The U.N. Security Council has demanded that Iran stop all uranium enrichment activity by April 28. Iran has rejected the demand, saying it has a right to develop the process.

"We'll talk with the rest of the Security Council members and others about the next steps," McClellan said. "Right now, the regime has been given an opportunity to comply with its obligations, and the most recent statements by the regime only further isolate itself and continue to show that it's moving in the wrong direction."

Speaking in his nationally televised presentation, Ahmadinejad called on the West "not to cause an everlasting hatred in the hearts of Iranians" by trying to force Iran to abandon uranium enrichment.

"At this historic moment, with the blessings of God Almighty and the efforts made by our scientists, I declare here that the laboratory-scale nuclear fuel cycle has been completed and young scientists produced enriched uranium needed to the degree for nuclear power plants Sunday," Ahmadinejad said.

"I formally declare that Iran has joined the club of nuclear countries," he told an audience that included top military commanders and clerics in the northwestern holy city of Mashhad.