Impasse With Afghanistan Raises Prospect of Total U.S. Withdrawal in 2014

American officials say they are preparing to suspend negotiations absent a breakthrough in the coming weeks, and a senior administration official said talk of resuming them with President Hamid Karzai’s successor, who will be chosen in elections set for next April, is, “frankly, not very likely.”

“The time to conclude for us is now,” the administration official said on Friday. In the absence of a deal, “this fall, we are going to have to make plans for the future accordingly.”

The impasse, after a year of talks, has increased the prospect of what the Americans call the zero option — complete withdrawal — when the NATO combat mission concludes at the end of 2014. That is precisely the outcome they hoped to avoid in Afghanistan, after having engaged in a similarly problematic withdrawal from Iraq two years ago.

Moreover, a complete withdrawal from Afghanistan could be far costlier than it was in Iraq. It would force European powers to pull their forces as well, risking a dangerous collapse in confidence among Afghans and giving a boost to the Taliban, which remain a potent threat.

It could also jeopardize vital aid commitments. Afghanistan is decades away from self-sufficiency — it currently covers only about 20 percent of its own bills, with the rest paid by the United States and its allies.

“It is a practical truth,” the administration official said, that without a deal, “our Congress would not likely follow through on the assistance promises we’ve made, nor would other partners.”

Many contentious matters in the talks have already been settled, like legal immunity for American troops, which is what scuttled the Iraq deal, Afghan and American officials said. Yet officials on both sides say two seemingly intractable issues remain.

The first is Afghanistan’s insistence that the United States guarantee its security, much like any NATO ally, and the second is Mr. Karzai’s refusal to allow American forces to keep searching in Afghanistan for operatives of Al Qaeda. Instead, he has proposed that the United States give its intelligence information to Afghan forces and let them do the searching, said Aimal Faizi, a spokesman for the president.

American officials have rejected both Afghan proposals. The security pact is especially problematic, they say, because it could legally compel American forces to cross the border into Pakistan, resulting in an armed confrontation with an ally — and a nuclear-armed power.

“The deal is like 95 percent done,” said another American official in Washington, “and both sides are holding out.”

President Obama, in an interview with The Associated Press published Saturday, made what appeared to be a reference to the impasse in the talks, saying that he would consider keeping troops in Afghanistan “if in fact we can get an agreement that makes sure that U.S. troops are protected, makes sure that we can operate in a way that is good for our national security.”

“If we can’t, we will continue to make sure that all the gains we’ve made in going after Al Qaeda we accomplish, even if we don’t have any U.S. military on Afghan soil,” Mr. Obama said in the interview, which was conducted Friday.

Mr. Faizi said Mr. Karzai was now taking a lead role in the talks. But, he cautioned, the Afghan leader could not agree to a deal that allowed American forces to raid Afghan villages and not at the same time go after militant havens in Pakistan.

“Killing people in homes and killing people in villages is bringing the war on terror to Afghans,” Mr. Faizi said in an interview. “This is not focusing on the root and support systems behind the terror.”

Only months ago, top American generals, including Gen. Martin E. Dempsey, the chairman of the Joint Chiefs of Staff, dismissed the possibility that negotiations could falter. The Obama administration has been far more ambiguous. Over the summer White House officials began to seriously weigh the zero option.