WASHINGTON — The Pentagon is considering several options to reduce the number of troops in Afghanistan, including one that would shift to a narrower counterterrorism mission, the top U.S. military officer told Congress on Wednesday.

Gen. Mark Milley, chairman of the Joint Chiefs of Staff, did not disclose any potential troop totals, but he agreed that leaving a minimal U.S. footprint in Afghanistan to battle terrorists is a potential move.

“We have multiple options, that’s one of them,” he said. The U.S. currently has about 13,000 troops in Afghanistan. About 5,000 of them are doing counterterrorism missions. The remainder are part of a broader NATO mission to train, advise and assist the Afghan security forces.

Earlier this week, a Washington Post report disclosed thousands of pages of documents revealing that government officials for years misled the public about failures in the Afghanistan war.