President Barack Obama is weighing options for keeping some U.S. troops in Afghanistan longer than planned, while maintaining the goal of ending military operations by 2017, according to an administration official.

The potential slowdown of the U.S. withdrawal, which would be the second delay in recent months, reflects the tenuous security situation in Afghanistan as the U.S. prepares to end military operations there. It comes after requests for flexibility from U.S. Army Gen. John Campbell and Afghan President Ashraf Ghani, according to the official, who requested anonymity to discuss internal deliberations.

Campbell, who's leading U.S. and North Atlantic Treaty Organization forces in Afghanistan, has drafted recommendations for increased training for the Afghan military as well as continued counterterrorism operations. Additionally, Ghani has asked for flexibility in the schedule for the drawdown of U.S. troops over the next two years.