Obama Says Al-Qaeda Still Greatest Threat To U.S.

A handout screen grab shows Al-Qaeda leader Osama bin Laden after he purportedly issued a new audio statement in January 2009.

SHANGHAI (Reuters) -- U.S. President Barack Obama has said the greatest threats to the United States continued to be terrorist networks like Al-Qaeda.

"I continue to believe that the greatest threat to the United States' security are the terrorist networks like Al-Qaeda," he told students at a town hall meeting in Shanghai.

"They have now moved over the border of Afghanistan and are in Pakistan, but they continue to have networks with other extremist organisations in that region and I do believe it is important for us to stabilize Afghanistan."