U.S. to go down to 2,500 troops in Afghanistan by early 2021 -Trump adviser

The United States will go down to 2,500 troops in Afghanistan early next year, U.S. national security adviser Robert O'Brien said on Wednesday, offering greater detail about the pace and scope of the drawdown from America's longest war.

"When President Trump took office, there were over 10,000 American troops in Afghanistan. As of today there are under 5,000 and that will go to 2,500 by early next year," O'Brien said, speaking at an event at the University of Nevada, Las Vegas.