KABUL, Afghanistan (AP) — U.S. Defense Secretary Mark Esper has arrived in Kabul to assess what comes next for the U.S. military in Afghanistan.

Peace talks with the Taliban are stalled and persistent violent attacks by the insurgent group and Islamic State militants have complicated the Trump administration's pledge to withdraw more than American 5,000 troops.

Esper tells reporters traveling with him that he believes the U.S. can reduce its force in Afghanistan to 8,600 without hurting the counterterrorism fight against al-Qaida and IS. But he says any withdrawal would happen as part of a peace agreement with the Taliban.

The U.S. has about 14,000 troops in Afghanistan as part of the U.S.-led coalition training and advising the Afghan forces and conducting counterterrorism operations against insurgents.