President Obama received a message last year, purporting to be from the elusive Taliban leader Mullah Muhammad Omar, in which he expressed an interest in opening talks that could end the war in Afghanistan, according to several current and former administration officials.
The message, which was received last summer, also pressed Mr. Obama on the issue of releasing Taliban prisoners held in American custody, these officials said. The communication, however, was not signed by Mullah Omar, and its authenticity could not be verified by American officials, some of whom have doubts about whether it came from him or from other Taliban leaders.
Still, as one senior official put it, "it tracks with what we've heard from other Taliban intermediaries." And a former senior official said the White House took the message seriously, whatever its source.
The disclosure of the message comes at a delicate moment, after the Taliban announced that they would open a political office in Qatar and the administration sent a senior diplomat to the Middle East to prepare the ground with allies for resuming preliminary negotiations with a representative of the group.
It also comes as lawmakers on Capitol Hill, and some inside the administration, have expressed opposition to releasing any Taliban prisoners. And it is surfacing as a campaign issue, with the Republican front-runner, Mitt Romney, saying that the nation should not be talking to its enemies.
The White House would not comment on the letter, which was first disclosed Friday by The Associated Press.
Among the hurdles in interpreting the message, officials said, are the mysteries around Mullah Omar, a shadowy figure who served as de facto leader of Afghanistan but who went into hiding after the September 2001 terrorist attacks and whose exact whereabouts and role in the Taliban leadership are not clear.
"The question has always been, 'Is Mullah Omar in the loop and in favor?' " said Bruce O. Riedel, a former intelligence analyst who led the White House's policy review on Afghanistan in 2009. "A message from him, or purportedly from him, would help answer that $64 million question."
American intelligence officials believe that Mullah Omar is in hiding in Pakistan, perhaps in Karachi. Some administration officials remain convinced that he plays a central role in directing the Taliban insurgency in Afghanistan, and that he would have to be involved in any credible reconciliation process.
If authentic, the message would not be the first time that Mullah Omar has reached out to American officials. In 1998, two days after an American cruise missile strike on an training camp for Al Qaeda in Afghanistan, he unexpectedly telephoned a State Department official, Michael E. Malinowski, who took the call on his porch at 2:30 a.m. According to declassified records, Mullah Omar demanded proof that Osama bin Laden, the intended target of the strike, was involved in terrorism.
The message to Mr. Obama, a former official said, indicated that Mullah Omar was serious about talks. But it also reveals his frustration that the administration seems resistant to releasing Taliban prisoners, the former official said. Under a plan being discussed, at least five senior Taliban prisoners held in the military jail in Guantánamo Bay, Cuba, would be transferred to house arrest in Qatar.
Among other hurdles is the role of Afghanistan's president, Hamid Karzai, whose views on the process have been unpredictable. This week, the Afghan government said it wanted to pursue its own talks with the Taliban in Saudi Arabia - a reflection, some officials said, of Mr. Karzai's frustration that he had been left out of the American effort to help open the office in Qatar. Adding to the complexity is the role of the Pakistanis, who have their own interests.
The negotiations could also be affected by Defense Secretary Leon E. Panetta's disclosure on Wednesday that American troops planned to end their combat role in Afghanistan in mid-2013, 18 months early - a signal, some analysts said, that the United States was rushing for the exit.
The Obama administration has defended the effort to explore talks with the Taliban, even as it concedes the risks.
"The reality is, we never have the luxury of negotiating for peace with our friends," said Secretary of State Hillary Rodham Clinton about the initiative earlier this month. "If you're sitting across the table discussing a peaceful resolution to a conflict, you're sitting across from people who you by definition don't agree with and who you may previously have been across a battlefield from."