The Obama administration’s internal deliberations about the future of the Afghan war were described by officials in Washington and Kabul who hold a range of views on how quickly the United States should leave Afghanistan and how many troops it should leave behind. Spokesmen for the White House and Pentagon declined to comment.

Within the Obama administration, the way the United States extricates itself from Afghanistan has been a source of tension between civilian and military officials since Mr. Obama took office. American commanders in Afghanistan have generally pushed to keep as many American troops in the country as long as possible, creating friction with White House officials urging a speedier military withdrawal.

But with frustrations mounting over the glacial pace of initiating peace talks with the Taliban, and with American relations with the Karzai government continuing to deteriorate, it is unclear whether the Pentagon and American commanders in Afghanistan would vigorously resist if the White House pushed for a full-scale pullout months ahead of schedule.

As it stands, the number of American troops in Afghanistan — around 63,000 — is scheduled to go down to 34,000 by February 2014. The White House has said the vast majority of troops would be out of Afghanistan by the end of that year, although it now appears that the schedule could accelerate to bring the bulk of the troops — if not all of them — home by next summer, as the annual fighting season winds down.

Talks between the United States and Afghanistan over a long-term security deal have faltered in recent months over the Afghan government’s insistence that the United States guarantee Afghanistan’s security and, in essence, commit to declaring Pakistan the main obstacle in the fight against militancy in the region.

The guarantees sought by Afghanistan, if implemented, could possibly compel the United States to attack Taliban havens in Pakistan long after 2014, when the Obama administration has said it hoped to dial back the C.I.A.’s covert drone war there.