KABUL, Dec. 3 (Xinhua) -- U.S. President Barack Obama told U.S. troops Friday in the Bagram Air Base in Afghanistan that progress has been made in Afghanistan but slow.

At the beginning of his speech, Obama expressed his gratitudes for U.S. troops here on behalf of the U.S. government.

Obama said progress in Afghanistan has been made but slow, nevertheless, the U.S. paid a a high price.

U.S. President Barack Obama meets with troops at Bagram Air Base, December 3, 2010.

However, he said that "your mission matters," the U.S. soldiers will bring down the Taliban's momentum.

"Because of you, we will prevail," Obama added.

Obama arrived in the Bagram Air Base Friday in a surprise visit.