Free nations must hold their ground against Iran's threats to restart its nuclear program, President Bush said today, so that "the Iranians [do] not have a nuclear weapon in which to blackmail and/or threaten the world."
Tension over the possibility of Iranian nukes rose this week as Iranian officials removed seals from three nuclear facilities. Iranian officials said they wanted to reactivate the plants for research purposes and to produce nuclear energy -- but not weapons.
Iran also has threatened to block short-notice U.N. inspections of the country's nuclear facilities if the United States and its allies push for U.N. sanctions against it.
Iran's threat to block the inspections came after Britain, France and Germany said that negotiations over Iran's nuclear facilities had hit a dead end, and that the time had come to refer Iran to the U.N. Security Council.
Iran's Foreign Minister Manouchehr Mottaki said all voluntary cooperation with international observers would end if Iran was referred to the council.
But President Bush, addressing the media at the White House alongside German Chancellor Angela Merkel, said it was "logical that a country, which has rejected diplomatic entreaties, be sent to the United Nations Security Council."
With Iran determined to restart its nuclear program, U.S. officials seemed ready for an international showdown.
Bush spoke of the need to "send a common message to the Iranians" about any potential moves toward acquiring nuclear weapons.
"It's very important for nontransparent societies not to have the capacity to blackmail free societies," Bush said. "We're thinking about how to lay the foundation for peace."
Added Merkel, through a translator: "We will certainly not be intimidated by a country such as Iran."
Bush's and Merkel's comments followed tense talk from other officials in the Bush administration.
"These provocative actions by the Iranian regime have shattered the basis for negotiation," Secretary of State Condoleezza Rice said.
Vice President Dick Cheney said U.N. sanctions against Iran were now at the top of the agenda.
At the Pentagon, Defense Secretary Donald Rumsfeld was asked whether military action was an option, but he wouldn't touch the question.
"I don't think my discussing that option is useful," Rumsfeld told reporters.
Russia also has renewed its call for Iranian officials to resume a moratorium on nuclear activities.
U.S. officials consider nuclear weapons for Iran a nightmare scenario, especially considering the erratic behavior of Ahmadinejad.
For instance, after a fiery anti-U.S. speech at the United Nations last fall, Ahmadinejad is said to have told religious leaders in Iran that he was surrounded by a glow of light, and that for 28 minutes, all the leaders of the world did not blink. He also has denied the Holocaust occurred and said Israel should be wiped off the map.
"That's unacceptable," Bush said of the threat against Israel. "And the development of a nuclear weapon, it seems like to me, would make them a step closer to achieving that objective."
Mottaki, Iran's foreign minister, has said Iran has the right under the Nuclear Nonproliferation Treaty to produce nuclear fuel, and Iran's state radio quoted Ahmadinejad as vowing to continue toward producing nuclear energy.
"Iranian people do not allow foreigners to block their progress," state-run radio quoted Ahmadinejad as saying, according to the Associated Press.
Speaking with ABC News' "Nightline," former President Clinton was asked about the likelihood of U.S. military strikes against Iran.
"I hope not," Clinton said. "And it's probably not in the immediate future, because Iran is a much more formidable opponent than Iraq -- and because we have our troops tied down in Iraq and Afghanistan, and they pretty much are stretched. On the other hand, potentially, it's a much more dangerous situation for us long-term than Iraq."
ABC News' Jonathan Karl and Terry Moran in Washington, and Linda Albin in London and Michael S. James in New York contributed to this report.