U.S. President Donald Trump has opened the door to troop increases in Afghanistan by giving Defense Secretary Jim Mattis the authority to set troop levels there, media report.
Army General John Nicholson, who leads U.S. and international forces in Afghanistan, has said he needs "a few thousand" more troops, up from 8,400 today.
The 3,000 to 5,000 additional forces being discussed at the Pentagon, some of which could be sent by U.S. allies, would be largely comprised of air crews and trainers to support Afghan forces.
Trump's decision to give the military wider discretion in prosecuting the 15-year war in Afghanistan on June 13 follows his grant of wider powers to U.S. generals directing U.S. forces in Iraq and Syria earlier this year.
It came as Mattis warned Congress that U.S.-backed Afghan forces were not winning the war against the Taliban, which he said was "surging" at the moment.
The increase in troops under consideration would leave U.S. forces well below their 2011 peak of more than 100,000. Some officials have questioned whether a modest increase would be enough to turn the tide of the war.