KABUL, Afghanistan — Afghan President Hamid Karzai says he favors a security agreement with America allowing some of its troops to remain after the end of 2014 but wants unspecified "guarantees."

Karzai provided no details when he spoke Thursday at a gathering on rural development. But he has said in the past that the United States must commit to boost Afghan security, strengthen its armed forces and provide long-term economic development assistance.

Karzai says the United States should pay for the agreement, a reference to a demand for rent to lease up to nine bases in Afghanistan. He didn't say how much money Afghanistan wants, but it's thought to be over $6 billion.

The United States has said it's not seeking permanent bases in Afghanistan. The agreement is expected by year's end.