WASHINGTON -- Senator Joseph I. Lieberman said yesterday that the United States should consider a military strike against Iran because of Tehran's alleged involvement in Iraq.

"I think we've got to be prepared to take aggressive military action against the Iranians to stop them from killing Americans in Iraq," Lieberman said. "And to me, that would include a strike over the border into Iran, where we have good evidence that they have a base at which they are training these people coming back into Iraq to kill our soldiers."

The United States accuses Iran of fostering terrorism and Tehran's nuclear ambitions have brought about international reproach.

Lieberman, the Democratic nominee for vice president in 2000 who now represents Connecticut as an independent, spoke of Iranians' role in the continued violence in Iraq.

"We've said so publicly that the Iranians have a base in Iran at which they are training Iraqis who are coming in and killing Americans. By some estimates, they have killed as many as 200 American soldiers," Lieberman said on CBS's "Face the Nation."

"Well, we can tell them we want them to stop that," Lieberman said. "But if there's any hope of the Iranians living according to the international rule of law and stopping, for instance, their nuclear weapons development, we can't just talk to them."

"If they don't play by the rules, we've got to use our force, and to me, that would include taking military action to stop them from doing what they're doing," he added.

Lieberman said much of the action could probably be done by air, although he would leave the strategy to the generals in charge. "I want to make clear I'm not talking about a massive ground invasion of Iran," Lieberman said.

To deal with Iran's nuclear ambitions, Democratic presidential hopeful Bill Richardson said tough negotiation is called for.

"I would talk to them, but I would build an international coalition that would promote and push economic sanctions on them," Richardson said on CNN's "Late Edition." "Sanctions would work on Iran. They are susceptible to disinvestment policy. They are susceptible to cuts, economic sanctions in commodities."

On Friday, Secretary of State Condoleezza Rice said that Iran's detention of at least four Americans is unwarranted but that it would not stop Washington from trying to engage Iran on other matters, including its disputed nuclear program and alleged support of insurgents in Iraq.

Iran yesterday confirmed that it has detained a fourth Iranian-American, a peace activist from California. The statement seems certain to further rile relations between the two countries.

Mohammad Ali Hosseini, the spokesman for Iran's foreign ministry, confirmed at his weekly briefing in Tehran that Iranian-American Ali Shakeri is being held.

© Copyright 2007 Globe Newspaper Company.