U.S. officials say the planned deployment of hundreds more U.S. Army trainers to Afghanistan early next year probably will increase the total number of American forces there to almost 16,000.

About 15,000 U.S. forces are in Afghanistan, after President Donald Trump ordered about 3,800 troops to the country this fall to increase efforts to advise Afghan forces and conduct counterterrorism missions. Those troops are already in Afghanistan.

The Army's new training brigade will head to Afghanistan early next year.

U.S. officials say Pentagon chief Jim Mattis has made clear he's committed to a force level based on needs, not an arbitrary number. So they believe the trainers will add to the U.S. total there.

The officials weren't authorized to publicly discuss the troop numbers and spoke on condition of anonymity.