On a swift, secretive trip to the war zone, President Barack Obama declared Tuesday night that after years of sacrifice the U.S. combat role in Afghanistan is winding down just as it has already ended in Iraq. "We can see the light of a new day," he said on the anniversary of Osama bin Laden's death and in the midst of his own re-election campaign.

"Our goal is to destroy al-Qaida, and we are on a path to do exactly that," Obama said in an unusual speech to America broadcast from an air base halfway around the world.

He spoke after signing an agreement with Afghan President Hamid Karzai to cover the decade after the planned final withdrawal of U.S. combat troops in 2014. Obama said American forces will be involved in counter-terrorism and training of the Afghan military, "but we will not build permanent bases in this country, nor will we be patrolling its cities and mountains."

In a blunt reminder of Afghanistan's fragile security situation, a series of explosions and gunfire erupted in Kabul just hours after Obama left, killing at least six people.