The comments came after the New York Times reported the White House is looking at speeding up the troop withdrawal to the “zero option.”
That means leaving no troops in Afghanistan.
Until now, U.S. and Afghan official have discussed plans to keep a small force behind to fight insurgents and train Afghan security personnel.
But the President has grown increasingly frustrated in dealing with Afghan President Hamid Karzai. Their relationship soured further last month after the U.S. and the Taliban planned peace talks. In response, Karzai cut off negotiations with the U.S. on the residual troop presence post-2014.