The number of U.S. troops in Afghanistan may drop well below 10,000 — the minimum demanded by the U.S. military to train Afghan forces — as the longest war in American history winds down, Obama administration officials briefed on the matter say.

Since Afghanistan's general election on April 5, White House, State Department and Pentagon officials have resumed discussions on how many American troops should remain after the current U.S.-led coalition ends its mission this year.

The decision to consider a small force, possibly less than 5,000 U.S. troops, reflects a belief among White House officials that Afghan security forces have evolved into a robust enough force to contain a still-potent Taliban-led insurgency. The small U.S. force that would remain could focus on counterterrorism or training operations.