Iran has successfully enriched uranium for the first time, Iranian President Mahmoud Ahmadinejad announced yesterday in a television broadcast. Ahmadinejad said Iran did not plan to develop nuclear weapons and asked the West not to try to force Iran to abandon uranium enrichment.

Israeli security sources described the announcement as a "major step forward" for Tehran. Nonetheless, it does not mean Iran is immediately capable of producing enough fuel to run a reactor or develop the material needed for a nuclear warhead. Uranium enrichment can produce either, but it must be carried out on a much larger scale, using thousands of centrifuges. Iran succeeded in enriching uranium to a level needed for fuel on a research scale - using 164 centrifuges, officials said.

Israel's chief of Military Intelligence, Amos Yadlin, told Haaretz last night that he hopes the international community "does not fall into the new trap that Iran has set, and accelerates the processes to stop the program."

"The Iranians want to present the world with a fait accompli, to determine that the debate over enrichment capabilities is behind them, and that enrichment is already being accomplished on Iranian soil," said Yadlin. "The announcements from Tehran are a bargaining chip. They are meant to move the debate to the next point - the extent of enrichment."

The announcement drew White House criticism for taking a key 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.

Ahmadinejad's announcement came a day ahead of a visit to Tehran by Mohamed ElBaradei, the head of the International Atomic Energy Agency, who is trying to resolve the West's standoff with Iran. The UN Security Council has demanded Iran stop all enrichment activity by April 28. Iran has rejected this, saying it has a right to do so.

MI chief Yadlin said he is convinced that Israel and the West do not know everything about the Iranian nuclear project. He thinks it is possible that Iran has a Plan B it has kept hidden from the West. "It has already been shown that there are activities that the Iranians have not reported to the IAEA," he said.

Israeli officials are no longer discussing the "point of no return" of Iranian nuclear power, focusing instead on "crossing the technological threshold" of completing the research and development stage. Various experts in the West have estimated that Iran will need six months to a year to complete this phase. It will then take one to three years for Iran to produce tens of thousands of centrifuges, which would bring Tehran very close to having its own nuclear bomb.

The U.S., meanwhile, hopes to 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."

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.