US Senator Joseph Lieberman said Sunday the United States should consider a military strike against Iran.

"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 on CBS's "Face the Nation". "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."

Lieberman said that "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… They can't believe that they have immunity for training and equipping people to come in and kill Americans,"

"We cannot let them get away with it," the independent senator for Connecticut stated. "If we do, they'll take that as a sign of weakness on our part and we will pay for it in Iraq and throughout the region and ultimately right here at home."