The new U.S. defense secretary has arrived in Kabul on an unannounced visit to Afghanistan.
Ash Carter said he wanted to talk to Afghan and U.S. officials to ensure a "lasting" success as U.S. troops withdraw.
U.S. forces ended their main combat mission in December 2014 but have remained in smaller numbers to continue training and advising the Afghans and to conduct counterterrorism strikes against extremist groups.
Carter said he expects to discuss the troop withdrawal plan with Afghan President Ashraf Ghani and get his assessment of how the U.S. military can best support the continued development of Afghan forces.
Carter said he looked forward to an update from Ghani and added the two would discuss Afghan government-led peace efforts with Taliban militants.
Senior Pakistani army, Afghan, and diplomatic officials said on February 19 the Afghan Taliban had signalled they were willing to open peace talks with Kabul.