[cnn-photo-caption image= http://i2.cdn.turner.com/cnn/2009/images/12/08/art.stan1208.gi.jpg caption="Gen. Stanley McChrystal spoke before members of Congress Tuesday about the outlook in Afghanistan."]
Washington (CNN) - Finding al Qaeda leader Osama bin Laden and rolling back a resurgent Taliban are necessary steps toward winning the war in Afghanistan, the top U.S. commander there told a Senate committee Tuesday.
Bin Laden remains at large more than eight years after the September 11, 2001, attacks on New York and Washington that triggered the Afghan war, and is widely believed to be hiding along the rugged border between Afghanistan and Pakistan. Gen. Stanley McChrystal, the commander of U.S. forces in Afghanistan,
said the world's most wanted terrorist is "an iconic figure" whose survival "emboldens al Qaeda as a franchising organization across the world."
"It would not defeat al Qaeda to have him captured or killed, but I don't think we can finally defeat al Qaeda until he is finally captured or killed," McChrystal told the Senate Armed Services Committee. But he said if bin Laden is hiding across the border, "It is outside of my mandate."
In addition, he said, pushing back the Taliban - which allowed al Qaeda to operate from Afghanistan before 9/11 - is a "prerequisite" for destroying the terrorist network.
"To pursue our core goal of defeating al Qaeda and preventing their return to Afghanistan, we must disrupt and degrade the Taliban's capacity, deny their access to the Afghan population, and strengthen the Afghan security forces," he said.
Updated: 4:16 p.m.