WASHINGTON (CNN) -- Iran remains a danger to the world even though it stopped a program to develop a nuclear weapon four years ago, President Bush said Tuesday.
President Bush tells reporters Tuesday that Iran still poses a threat to the world.
"Iran was dangerous, Iran is dangerous and Iran will be dangerous if they have the knowledge necessary to make a nuclear weapon," Bush said, pointing out that Tehran continues to try to enrich uranium for civilian purposes and therefore develop technology that could be used for a weapon.
A declassified summary of a National Intelligence Estimate released by the U.S. government on Monday said Iran had stopped working toward a nuclear weapon in 2003 and is unlikely to be able to produce enough enriched uranium for a bomb until at least 2010.
Enriched uranium at low concentrations can be used to fuel nuclear power plants, but much higher concentrations are needed to yield a nuclear explosion.
The new estimate is less severe than a 2005 report that judged the Iranian leadership was "determined to develop nuclear weapons despite its international obligations and international pressure."
Earlier Tuesday, Iran ripped the Bush administration for rhetoric that came before Monday's release of the estimate.
"U.S. officials have so far inflicted ... damage on the Iranian nation by spreading lies against the country and by disturbing public opinion, therefore, they have to pay the price for their action," Iranian government spokesman Gholam-Hossein Elham is quoted as saying on the Web site of the official Islamic Republic News Agency.
In another posting, IRNA called the updated estimate "a necessary and positive step in Tehran-Washington relations, but undoubtedly is not sufficient."
"The U.S. administration should know that only admitting a mistake is not enough," the IRNA report said.
But Bush said Tuesday he saw the latest estimate on Iran as "a warning signal." Watch why Bush says he sees a danger in the report »
"What's to say they couldn't start another covert nuclear weapons program?" Bush asked.
The latest estimate shows "Iran needs to be taken seriously as a threat to peace," Bush said. See how the 2005 and 2007 estimates differ »
U.S. national security adviser Stephen Hadley said Monday that Iran remains a serious threat.
"We have good reason to continue to be concerned about Iran developing a nuclear weapon even after this most recent National Intelligence Estimate," he said. "In the words of the NIE, quote, Iranian entities are continuing to develop a range of technical capabilities that could be applied to producing nuclear weapons, if a decision is made to do so."
Hadley said U.S. policy toward Iran has not changed because of the new report.
"If we want to avoid a situation where we either have to accept Iran ... with a path to a nuclear weapon, or the possibility of having to use force to stop it, with all the connotations of World War III -- then we need to step up the diplomacy, step up the pressure, to get Iran to stop their so-called civilian uranium enrichment program," he said. "That's our policy going forward -- no change."
Britain on Tuesday also called for continued pressure on Iran.
"The report confirms that we were right to be worried about Iran seeking to develop nuclear weapons, and it also shows that the sanctions program and international pressure were having some effect," a spokesman for Prime Minister Gordon Brown said.
Israeli Defense Minister Ehud Barak echoed Bush's comments Tuesday.
"Iran is a main threat to the world and Israel," Barak said. "The entire world and the state of Israel should prepare to deal with this threat and thwart it."
Iran has insisted its nuclear program is strictly aimed at producing electricity, and the country has refused the U.N. Security Council's demand to halt its enrichment program.
Iran's ambassador to the International Atomic Energy Agency, Ali Asghar Soltanieh, said Tuesday that even the allegations that Tehran was pursuing a nuclear weapon up to 2003 were false.
"I categorically reject any allegation that Iran has had before, has now and will have [such a program] because a nuclear weapon is not in our defense decree," Soltanieh said.
"We are of the belief that a nuclear weapon would create a vulnerability and therefore we are and have and will be against nuclear weapons," he said.
The IAEA, the U.N. nuclear watchdog, has reported that Iran is cooperating with inspectors by providing access to declared nuclear material, documents and facilities. However, the agency also said Iran is withholding information in other areas, and as a result, the IAEA's knowledge about the status of the program is "diminishing."
Iran says its uranium enrichment work is allowed under the 1968 Non-Proliferation Treaty. The U.N. Security Council has passed two rounds of sanctions against Tehran, but Washington missed its goal of reaching consensus on tighter restrictions by the end of November, the State Department said last week. E-mail to a friend