The United States demanded that Iran (search) come clean about its nuclear program, insisting on Wednesday that it submit to more intrusive inspections after what it called a "deeply troubling" report from the U.N. nuclear agency.

In Tehran, Iranian President Mohammad Khatami (search) said that his country was not trying to build nuclear weapons. He repeated that Iran was prepared to allow unfettered inspections by the nuclear watchdog agency but expected the international community to recognize Iran's right to acquire advanced peaceful nuclear technology.

"We confidently declare that we are not after nuclear weapons," Khatami said. "Actually we don't believe that atomic weapons can bring security to a nation against countries possessing this kind of weapons."

Khatami spoke shortly before President Bush underlined Washington's concerns, saying he and other world leaders will not tolerate nuclear weapons in Iran. He also urged Tehran to treat protesters seeking the ouster of the Islamic government with "the utmost of respect."

"The international community must come together to make it very clear to Iran that we will not tolerate construction of a nuclear weapon," Bush told reporters at the end of a meeting in the White House Cabinet Room. "Iran would be dangerous if it had a nuclear weapon."

U.S. Ambassador Kenneth Brill criticized Iran in a sharp statement delivered to the International Atomic Energy Agency (search)'s board, noting that the United Nations report found that the Islamic government failed to declare how it used nuclear material.

"The United States finds the substance of the ... report deeply troubling," Brill said. "Although the investigations are continuing, the report already confirms that Iran's nuclear program is cause for great concern."

The United States wants the nuclear agency to declare Iran in violation of the Nuclear Nonproliferation Treaty. The matter could then be sent to the U.N. Security Council for possible action.

The three-hour hearing in Vienna, with representatives from nearly two dozen countries speaking, ended without a decision.

Brill appealed to the board to meet in a special session to consider the issue and said it was important to note that the IAEA -- and not the Iranians -- had come forward with the revelations.

"Without the outside revelations, Iran's extensive nuclear program would still be proceeding on a largely clandestine basis," he said. "Can the IAEA or anyone else be confident under these circumstances that there are no other clandestine facilities that have yet to be revealed?"

Brill's pointed remarks came just hours after Iran's representative, Ambassador Ali Akbar Salehi, rejected allegations that his government failed to honor promises made under the treaty, which aims to stop the spread of nuclear weapons.

"Iran considers the acquiring, development and use of nuclear weapons inhuman, immoral, illegal and against its very principles," he said. "They have no place in Iran's defensive doctrine."

However, Salehi acknowledged that the U.N. nuclear agency and the Islamic country had different interpretations of regulations regarding the import and use of nuclear material.

The Iranian ambassador suggested his government was being singled out. "We should wisely join in all our forces to avoid the practice of double standards," he said.

In the days leading to the meeting, the United States was having trouble rounding up support for a tough resolution condemning Iran, Western diplomats said on condition of anonymity.

Nonaligned countries like Malaysia declined to support a tough line. Strong U.S. allies are eager to avoid undermining Iranian reformers like Salehi rather than risk strengthening hard-liners.

A diplomat suggested it was possible the United States could get a statement from the board's chair with strong language asking Iran to comply with more stringent inspections, if not a resolution.

Board members won't reveal what they have decided until after the session ends later this week.

Iran insists its nuclear program is intended to produce electricity, which will be needed as oil supplies decline. Tehran has said it would agree to provide more access and information to inspectors, but only in exchange for more advanced nuclear technology.

In Tehran on Wednesday, Khatami said America's open support for student-led protests in Iran was "incorrect" and only promoted national unity.

"The incorrect position adopted by the Americans, irrespective of the fact that it was an act of interference in Iran's internal affairs, fortunately caused greater national solidarity," Khatami told reporters after meeting with the Afghan and Tajik presidents.

The comments were Khatami's first following a week of fierce clashes between pro-clergy hard-line militants and student-led protesters that left dozens injured and many more behind bars.