Washington ? President Barack Obama will not commit more U.S. troops to Afghanistan until he is convinced that the central government can be a credible and effective U.S. partner, a senior White House aide said Sunday.

But it was unclear whether Obama intends to accept the recommendation by the top U.S. commander in Afghanistan, Gen. Stanley McChrystal, for thousands more American troops and other resources in the 8-year struggle to stabilize Afghanistan.

The central question before Obama, chief of staff Rahm Emanuel said, is “not how much troops you have, but whether in fact there’s an Afghan partner.”

The issue of developing an effective Afghan central government has dogged the U.S. mission virtually from the war’s start after the attacks against the U.S. on Sept. 11, 2001. It gained new urgency after an Aug. 20 presidential election marred by charges of ballot-stuffing and voter coercion.

An election fraud investigation could lead to a runoff election between President Hamid Karzai and his top challenger, former Foreign Minister Abdullah Abdullah.

A second round of balloting would have to be held before winter, which traditionally begins in mid-November. Once heavy snows block mountain passes, thereby limiting voter access to polling places, a runoff would have to wait until spring, leaving the country in political limbo for months as the Taliban gains strength.