TEHRAN, Iran (CNN) -- Iranian President Mahmoud Ahmadinejad on Wednesday called a U.S. intelligence report that downgraded his country as a nuclear threat "a declaration of victory" for the Iranian nuclear program.
President Mahmoud Ahmadinejad said earlier U.S. reports were based on "shoddy intelligence."
But President Bush said later that Iran needs to "come clean" on its nuclear program by detailing past actions and future intentions.
"The Iran nuclear issue is a problem and continues to be a problem," Bush said.
Bush called on Tehran to suspend nuclear enrichment that it says is for civilian purposes but that the U.S. leader says could covertly be converted for military use.
Ahmadinejad said this week's U.S. National Intelligence Estimate saying Iran had stopped nuclear weapons work in 2003 was vindication.
"The report said clearly that the Iranian people were on the right course," Ahmadinejad said, according to a report from the official Islamic Republic News Agency.
"Today, Iran has turned to a nuclear country, and all world countries have accepted this fact," the Iranian president was quoted as saying.
During a televised speech made from Ilam province in western Iran, Ahmadinejad said earlier reports from the United States had been based on "shoddy intelligence."
The Bush administration has for years warned that Iran's development of nuclear power plants and enriched uranium masked an effort to produce an nuclear bomb.
Top U.S. officials have called the prospect of a nuclear-armed Iran "unacceptable."
But in a report released Monday, U.S. intelligence agencies concluded that Iran had suspended nuclear weapons work in 2003 and was unlikely to produce enough weapons-grade uranium for a bomb until at least 2010. The assessment reverses a 2005 National Intelligence Estimate that found the Islamic republic was "determined to develop nuclear weapons despite its international obligations and international pressure."
The revised U.S. conclusions come after months of accusations that the Bush administration was attempting to maneuver the United States into a conflict with Iran, which it also accuses of meddling in the war in Iraq. In October, the United States designated elements of Iran's Revolutionary Guard Corps as supporters of terrorism.
Iran declared its ability to produce enriched uranium for a civilian energy program in 2006. Enriched uranium at low concentrations can be used to fuel nuclear power plants, but much higher concentrations are needed to produce a weapon.
Iran has denied working to produce nuclear weapons, but it has refused the U.N. Security Council's demand that it halt uranium enrichment work.
The United States and its European allies are pushing for tighter sanctions against Tehran as a result of that refusal, and Bush said Tuesday that the latest estimate "makes it clear that the strategy we have used in the past is effective."
On Wednesday, Bush said U.S. officials had been in touch with leaders in Germany, Britain, France and Russia and had received support for continued pressure on Tehran.
The U.S. president said Iran must reveal details about its nuclear past and plans or face international isolation.
"The Iranian government has more to explain about its nuclear intentions and past actions, especially the covert nuclear weapons program pursued into the fall of 2003, which the Iranian regime has yet to acknowledge," Bush said. E-mail to a friend