BAGRAM AIR FIELD, Afghanistan - President Barack Obama has slipped into Afghanistan to see U.S. troops serving in America's longest war.
Air Force One arrived Sunday at the main U.S. base in Afghanistan after an overnight flight from Washington.
Obama is expected to spend just a few hours at Bagram Air Field. He has no plans to meet with outgoing Afghan President Hamid Karzai. Karzai has had a rocky relationship with the White House.
Obama is considering keeping a small number of U.S. troops in Afghanistan for training and counterterrorism missions beyond year's end. The U.S. and NATO are withdrawing most of their forces by then.
Karzai has refused to sign a security agreement that the U.S. needs to keep troops in Afghanistan. The candidates running to succeed Karzai say they will sign.