WASHINGTON — WASHINGTON -- President Bush warned yesterday that Iran remained a threat despite an intelligence assessment that it halted a covert program to develop nuclear weapons four years ago, as the administration struggled to save a diplomatic process now in disarray.
Again facing criticism over the handling - and meaning - of intelligence reports, Bush said the new assessment underscores the need to intensify international efforts to prevent Iran from acquiring a nuclear weapon.
He said that Iran could not be entrusted with acquiring even the scientific knowledge to enrich uranium for peaceful civilian use, explicitly declaring for the first time what has been an underlying premise of his policy. He also appeared to rule out any new diplomatic initiative with the president of Iran, Mahmoud Ahmadinejad.
"Look, Iran was dangerous, Iran is dangerous, and Iran will be dangerous, if they have the knowledge necessary to make a nuclear weapon," Bush said during a news conference dominated by questions about the fallout from the assessment, known as a National Intelligence Estimate. "What's to say they couldn't start another covert nuclear weapons program?"
The assessment reversed one in 2005 that asserted that Iran was "determined to develop nuclear weapons," with American intelligence agencies now saying they do not know whether Iran intends to take that step.
Bush said the reversal arose from "a great discovery" by U.S. intelligence agencies, but neither he nor other officials would explain. Current and former U.S. and foreign officials said the findings were based on intercepted communications and accounts provided by individuals with access to information about Iran's nuclear program.
Rep. Jane Harman, a California Democrat, said she read the classified version of the report yesterday and described the intelligence agencies' work as "a sea change" from the 2005 assessment in the quality of its analysis and presentation of facts. Asked about the basis for the new findings, she said: "I think we have some better sourcing. That's all I can say."
Bush's remarks did little to silence critics, who have accused him of hyping the case for confronting Iran. Nor did it ease concerns of some allies. Sen. Lindsey Graham, a South Carolina Republican, said he was perplexed by the new assessment and suspicious of the new evidence. "We should all look under the hood of these intelligence reports," he said.
Bush and his senior aides spent the day trying to hold together the fragile coalition of world powers seeking to rein in Iran's nuclear ambitions. Bush telephoned President Vladimir V. Putin of Russia, who has voiced skepticism about an aggressive U.S. effort to punish and isolate Iran.
Secretary of State Condoleezza Rice also telephoned her counterparts from the five other countries that have been pursuing U.N. sanctions against Iran to urge that the coalition continue work on a new round of increasingly tighter sanctions.
"This report is not an 'OK, everybody needs to relax and quit' report," Bush said. "This is a report that says what has happened in the past could be repeated and that the policies used to cause the regime to halt are effective policies.
"And let's keep them up. Let's continue to work together."
A senior administration official said the intelligence assessment on Iran was a setback in the effort to persuade China to endorse a new round of sanctions at the U.N. Security Council. While there had been indications over the weekend that the Chinese might drop their opposition to such a move, it appeared yesterday that they were reconsidering again, the official said.
President Bush will visit the Middle East in early January as he presses the Israelis and the Palestinians to restart moribund peace talks, the White House said yesterday.
White House spokesman Gordon Johndroe would not release any details of Bush's itinerary. However, an Israeli television station said the president would visit Israel.
Last week, Bush played host to a high-profile Middle East peace conference in Annapolis, where Israeli Prime Minister Ehud Olmert and Palestinian Authority President Mahmoud Abbas told international backers and skeptical Arab neighbors that they were ready to resume bargaining toward achieving an independent Palestinian homeland.