WASHINGTON — Increasingly frustrated by his dealings with President Hamid Karzai, President Obama is giving serious consideration to speeding up the withdrawal of United States forces from Afghanistan and to a “zero option” that would leave no American troops there after next year, according to American and European officials. 
 
 Mr. Obama is committed to ending America’s military involvement in Afghanistan by the end of 2014, and Obama administration officials have been negotiating with Afghan officials about leaving a small “residual force” behind. But his relationship with Mr. Karzai has been slowly unraveling, and reached a new low after an effort last month by the United States to begin peace talks with the Taliban in Qatar. 
 
 Mr. Karzai promptly repudiated the talks and ended negotiations with the United States over the long-term security deal that is needed to keep American forces in Afghanistan after 2014. 
 
 A videoconference between Mr. Obama and Mr. Karzai designed to defuse the tensions ended badly, according to both American and Afghan officials with knowledge of it. Mr. Karzai, according to those sources, accused the United States of trying to negotiate a separate peace with both the Taliban and their backers in Pakistan, leaving Afghanistan’s fragile government exposed to its enemies. 
 
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 Mr. Karzai had made similar accusations in the past. But those comments were delivered to Afghans — not to Mr. Obama, who responded by pointing out the American lives that have been lost propping up Mr. Karzai’s government, the officials said. 
 
 The option of leaving no troops in Afghanistan after 2014 was gaining momentum before the June 27 video conference, according to the officials. But since then, the idea of a complete military exit similar to the American military pullout from Iraq has gone from being considered the worst-case scenario — and a useful negotiating tool with Mr. Karzai — to an alternative under serious consideration in Washington and Kabul. 
 
 The officials cautioned that no decisions had been made on the pace of the pullout and exactly how many American troops to leave behind in Afghanistan. The goal remains negotiating a long-term security deal, they said, but the hardening of negotiating stances on both sides could result in a repeat of what happened in Iraq, where a deal failed to materialize despite widespread expectations that a compromise would be reached and American forces would remain. 
 
 “There’s always been a zero option, but it was not seen as the main option,” said a senior Western official in Kabul. “It is now becoming one of them, and if you listen to some people in Washington, it is maybe now being seen as a realistic path.” 
 
 The official, however, said he hoped some in the Karzai government were beginning to understand that the zero option was now a distinct possibility, and that “they’re learning now, not later, when it’s going to be too late.” 
 
 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. 
 
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 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. 
 
 Mr. Karzai also wants the Obama administration to specify the number of troops it would leave in Afghanistan after 2014 and make a multiyear financial commitment to the Afghan Army and the police. 
 
 The White House announced last month that long-delayed talks with the Taliban would begin in Doha, Qatar, where the Taliban opened what amounts to an embassy-in-exile, complete with their old flag and a plaque with their official name, “The Islamic Emirate of Afghanistan.” 
 
 But the highly choreographed announcement backfired, with Afghan officials saying the talks gave the insurgents undeserved legitimacy and accusing the Obama administration of negotiating behind Mr. Karzai’s back. 
 
 To the surprise of American officials, Mr. Karzai then abruptly ended the negotiations over a long-term security deal. He has said the negotiations would not resume until the Taliban met directly with representatives of the Afghan government, essentially linking the security negotiations to a faltering peace process and making the United States responsible for persuading the Taliban to talk to the Afghan government. 
 
 The Taliban have refused for years to meet directly with Afghan government negotiators, deriding Mr. Karzai and his ministers as American puppets. 
 
 There have been other points of contention as well. Meeting with foreign ambassadors recently, Mr. Karzai openly mused that the West was to blame for the rise of radical Islam. It was not a message that many of the envoys, whose countries have lost thousands of people in Afghanistan and spent billions of dollars fighting the Taliban, welcomed. 
 
 The troop decisions are also being made against a backdrop of growing political uncertainty in Afghanistan and rising concerns that the country’s presidential election could either be delayed for months or longer, or be so flawed that many Afghans would not accept its results. 
 
 Preparations for the election, scheduled for next April, are already falling behind. United Nations officials have begun to say the elections probably cannot be held until next summer, at the earliest. If the voting does not occur before Afghanistan’s mountain passes are closed by snow in late fall, it will be extremely difficult to hold a vote until 2015. 
 
 Of potentially bigger concern are the rumors that Mr. Karzai, in his second term and barred from serving a third, is trying to find a way to stay in power. Mr. Karzai has repeatedly insisted that he plans to step down next year. 
 
 The ripple effects of a complete American withdrawal would be significant. Western officials said the Germans and Italians — the two main European allies who have committed to staying on with substantial forces — would leave as well. Any smaller nations that envisioned keeping token forces would most likely have no way of doing so. 
 
 And Afghanistan would probably see far less than the roughly $8 billion in annual military and civilian aid it is expecting in the coming years — an amount that covers more than half the government’s annual spending. ||||| (CNN) -- President Barack Obama is seriously considering withdrawing all U.S. troops from Afghanistan in 2014, a senior administration official told CNN. 
 
 The official's comments came after The New York Times reported the administration was looking at speeding up the troop withdrawal to the "zero option," leaving no U.S. troops in Afghanistan. 
 
 Until now, U.S. and Afghan officials had been discussing plans to keep a small force behind to fight insurgents and to train Afghan security personnel. 
 
 But Obama has, in recent months, grown increasingly frustrated in dealing with Afghan President Hamid Karzai. 
 
 Their relationship soured further last month after the United States and the Taliban planned peace talks. In response, Karzai cut off negotiations with the United States on the residual troop presence post-2014. 
 
 A "zero option" has always been among the scenarios the United States envisioned. But the new revelation means that it could be a very possible one now. 
 
 Pentagon spokesman George Little said Tuesday that Obama has not made a decision on U.S. troop levels in Afghanistan beyond 2014. 
 
 "We are continuing discussions" with Afghanistan about carrying out post-combat missions, Little said. "We continue to work through issues," he said, adding, "We believe we can work through them." 
 
 If the United States pulls out all its troops, it will be a situation similar to that in Iraq. 
 
 The refusal by the Iraqi government to extend legal protections for U.S. troops after the end of the war in Iraq was a major reason the United States left the country with no residual military training force. 
 
 Karzai has said he would like for U.S. troops to remain after the end of the NATO mission. But he also has been highly critical of the troops over the years, following incidents in which U.S. forces have killed civilians. 
 
 CNN's Adam Levine contributed to this report.
– President Obama is so sick of dealing with Afghanistan's President Hamid Karzai that he is seriously considering bringing American military involvement in the country to a speedy and complete end, senior administration officials tell CNN and the New York Times. The "zero option" of leaving no American troops in the country at all after the end of 2014 has been raised before, but it is now being seen as "a realistic path" and is one of the main options under consideration as relations with Karzai deteriorate, a senior US official in Kabul says. Tensions between Obama and Karzai have been going downhill fast since the US began an effort last month to hold peace talks with the Taliban, insiders say, and a recent videoconference between the two ended with the relationship worse than ever after Karzai accused the US of abandoning the Afghan government and Obama responded by pointing out the American lives lost keeping his regime in power. The number of US troops in Afghanistan is set to go from the current 63,000 to 34,000 by next February. Most of those are expected to be gone by the end of 2014, but it is now possible that they could all be home by the end of next summer.