President Obama addressed the American people from Bagram Air Base, outside the Afghan capital, Kabul, where he landed Tuesday on an unannounced visit.

"My fellow Americans, we have traveled through more than a decade under the dark cloud of war. Yet here, in the pre-dawn darkness of Afghanistan, we can see the light of a new day on the horizon. The Iraq War is over," President Obama said.

"The number of our troops in harm’s way has been cut in half, and more will be coming home soon. We have a clear path to fulfill our mission in Afghanistan, while delivering justice to al Qaeda."

Tuesday marked the anniversary of the raid that killed Osama bin Laden and the President commented on the raid in his speech, saying that "over the last three years...we devastated al Qaeda’s leadership, taking out over 20 of their top 30 leaders. And one year ago, from a base here in Afghanistan, our troops launched the operation that killed Osama bin Laden."

The President landed at Bagram after nightfall on Tuesday and then took a helicopter to Kabul, where he met with Afghan President Hamid Karzai and the two leaders signed a strategic partnership agreement.

The agreement pledges continued U.S. support for Afghanistan for a decade after the scheduled combat troop withdrawal in 2014 and includes mutual commitments in the areas of "protecting and promoting shared democratic values, advancing long-term security, reinforcing regional security and cooperation, social and economic development and strengthening Afghan institutions and governance," according to the White House.

The agreement does not commit the U.S. to specific troop levels or levels of funding, the White House said.

The timing of the trip was driven by the Presidents' desire to sign the agreement prior to the NATO Summit in Chicago later this month, according to Senior administration officials.

Prior to his address, the President spoke to troops stationed at Bagram.

“We're not going to do it overnight. We're not going to do it irresponsibly.  We're going to make sure that the gains, the hard-fought gains that have been made are preserved. But the reason we're able to do that is because of you. The reason that the Afghans have an opportunity for a new tomorrow is because of you.  And the reason America is safe is because of you,” President Obama said, speaking on the transition to Afghan responsibility for Afghan security.

In a statement, Defense Secretary Leon Panetta called the agreement "a tangible sign of the strength and the resilience of the partnership that has been built between the United States and the Afghan people, and the significant progress that has been made by American, international and Afghan forces in building an Afghanistan that can secure and govern itself."