Republican rival John McCain responded in Nashville that Obama was foolishly announcing he would attack another country.

Obama said problems have mounted in Afghanistan because the U.S. military was sent into Iraq "when we hadn't finished the job of hunting down (Osama) bin Laden and crushing al-Qaida. So what happened was we got distracted ... and ultimately bin Laden escaped, set up base camps (across the border) in the mountains of Pakistan" and was attacking U.S. troops.

He added, "If we have Osama bin Laden in our sights and the Pakistani government is unable or unwilling to take them out, then I think that we have to act, and we will take them out."

McCain said Obama's rhetoric was misplaced. "Teddy Roosevelt used to say ... talk softly but carry a big stick. Senator Obama likes to talk loudly. In fact, he said he wants to announce that he's going to attack Pakistan. Remarkable."

McCain said "if ... you're trying to gain the support of another country, then you want to do anything you can that they would act in a cooperative fashion. When you announce that you're going to launch an attack into another country, it's pretty obvious that you have the effect that it had in Pakistan. It turns public opinion against us."