The White House stuck to its guns Monday, insisting it had clear evidence that Tehran approved the shipment of weapons — including deadly bomb-making materials — to Shiite militants for use against U.S. forces in Iraq.
At the same time, Press Secretary Tony Snow said critics are using the evidence presentation to try to "whip this up" into a story about the United States being on the verge of armed conflict with Iran.
"This is clearly a case where people are hyping something up. I don't know how much clearer we can be. We're not getting ready for war in Iran but what we are doing is protecting our own people," Snow said.
Snow told reporters the United States is confident the Islamic Republic is approving the weapons shipments to Iraq. He added that if Iran's president wants to change that, he could do so quickly and easily.
"We would love for the Iranians, in fact, to be a force for peace in the region. It would be good for them and it would be good for the region. And we've laid out very strong inducements that we think make it perfectly sensible for them to do so," he said.
In Iran, President Mahmoud Ahmadinejad rejected U.S. accusations about Iran's involvement. Speaking to ABC News on Monday, Ahmadinejad said his country is opposed to any kind of conflict in Iraq. He also suggested the United States is trying to draw Iran into a conflict.
"The U.S. administration and (President) Bush are used to accusing others," Ahmadinejad said in the interview with Diane Sawyer.
"I think it really is the Iranians who have a problem with the truth, to put it bluntly," responded State Department spokesman Sean McCormack. "They are the ones who have to hide in the shadows with respect to their links to terrorist organizations, it's not the United States or its friends and allies."
On Sunday, U.S. military officials in Baghdad displayed evidence of Iranian-made explosively formed projectiles, or EFPs, which can penetrate heavy armor used in tanks and are responsible for the deaths of 170 American troops in Iraq since 2004.
Officials said a number of the EFPs found before exploding contained C-4 explosive that has been chemically traced to Iran. In addition, the munitions reveal that the "machining process" required to make the projectile and the triggering devices also come from Iran.
The officials said the Iranian supplies are mostly going to surrogates here, primarily Mahdi Army militia members. The Mahdi militia is faithful to Shiite cleric Muqtada al-Sadr.
Officials said they developed the information in part on the arrest of the five operatives in Irbil in January and the seizure of documents during a December raid on the Hakim compound in Baghdad.
Democratic Sen. Jack Reed of Rhode Island said tracing the weapons to Iran does not mean Iran's government is responsible for shipping them.
"This is a very difficult situation to try and decipher, and as you the administration for days promising they would have a more comprehensive report. I think what they are discovering is it's hard to come up with credible, definitive answers as to what the Iranians are up to," Reed said.
Other U.S. lawmakers said the Bush administration will have to deal with the apparent meddling, but not through the military option.
"We ought to confront them with the specifics of the evidence. Lay it on the line. Make them examine the evidence and issue specific denials if they can. That's a start," said Sen. Arlen Specter, R-Pa.
Specter said Iran has a history of involving itself with terrorist activities around the world, but the U.S. should try to improve its relations with the country.
"We know that without negotiations, we're not going to solve our differences with Iran, and with them, we might. Listen, the old saying is accurate: Keep your friends close and your enemies closer," Specter told FOX News.
Sen. Trent Lott, R-Miss, agreed that Iran must be stopped from sending weapons to Iraq, but cautioned against force.
"That doesn't mean we're going to necessarily try to hit a plant where they may be being constructed, but we're going to have to be more vigilant in finding out exactly where they're coming from and interdicting them because they are killing Americans," he said.
McCormack said the evidence presented was not being used as a justification for war, it was merely a presentation about the current and ongoing threat to U.S. troops in Iraq.
"The activities of our forces in Iraq, with respect to the networks that support the manufacture and deployment of these kinds of devices, are designed to stop those activities. That's what they're there for. It's a force-protection issue. We're not trying to make this into anything more than it is, but it is a serious issue because it involves the lives of our troops deployed in Iraq," he said.
Rep. Chris Shays, R-Conn., said he's not surprised by the conclusions in the evidence report but suggested that even if the Bush administration wanted to attack Iran, it couldn't.
"I don't think we'll invade Iran. I don't think we have, really, the capability to sustain that," he said.
Shays and Rep. Adam Schiff, D-Calif., suggested more aggressive diplomatic efforts to stop Iran from sending munitions to Iraq. Schiff also recommended trying to seal up the porous border between Iraq and its neighbors Iran and Syria.
FOX News' Mike Emanuel and John Fiegener and The Associated Press contributed to this report.