American and Afghan officials say they now must turn to working out a deal that would keep a residual American force here to continue training Afghan soldiers and tracking down insurgents after 2014. Talks on the arrangement have not yet begun, American officials say. Estimates of the number of troops that could stay vary from as little as 10,000 to as many as 25,000 or 30,000.

But Mrs. Clinton reiterated on Saturday that Washington did envision keeping American troops in Afghanistan, where they would provide the kind of air power and surveillance capabilities needed to give Afghan forces an edge over the Taliban.

“This is the kind of relationship that we think will be especially beneficial as we do the transition and as we plan for the post-2014 presence,” she said. “It will open the door to Afghanistan’s military to have a greater capability and a broader kind of relationship with the United States and especially the United States military.”

Mrs. Clinton made a short stop in Kabul en route to Tokyo, where an international conference will be held to raise money to support the Afghan government after 2014. At the American Embassy, she praised the work done by civilians in the war. State Department officials said that her remarks were intended to rebut what many in the State Department consider unfair criticism of their work in Afghanistan, where they have often been portrayed as not carrying their weight compared with the military.

But American soldiers and civilians alike have faced one common struggle: assuaging Afghan fears of abandonment. Many here fear that the country is headed toward a repeat of the early 1990s, when the fall of the Soviet-backed government, coupled with an American pullback from the region, left Afghanistan mired in a brutal civil war.

The Taliban grew out of the chaos, and they quickly took over much of the country.

Along with reassuring Afghans, Mrs. Clinton made clear that she was also sending a message to the Taliban.

The alliance and other American commitments to Afghanistan “should make clear to the Taliban that they cannot wait us out,” she said, according to a copy of her prepared remarks. “They can renounce international terrorism and commit to an Afghan peace process, or they will face the increasingly capable Afghan national security forces, backed by the United States.”