By Missy Ryan and Warren Strobel
WASHINGTON (Reuters) - The White House received a letter last year purported to come directly from Mullah Omar, the reclusive leader of the Taliban, asking the United States to deliver militant prisoners whose transfer is now at the heart of the Obama administration's bid to broker peace in Afghanistan.
The unusual message kicked off a debate within the administration about whether it was truly authored by the mysterious one-eyed preacher believed to be directing the Taliban from hiding in Pakistan -- and its meaning for U.S. efforts to forge a negotiated end to 10 years of war.
"As we have engaged various interlocutors as part of the reconciliation process, we have received a variety of messages that were represented as being from senior members of the Taliban," an administration official said on condition of anonymity.
"However, we haven't received a letter that we are certain is from Mullah Omar."
The message reportedly expressed impatience that the White House had not yet transferred five former senior Taliban officials out of Guantanamo Bay military prison.
U.S. officials have been considering moving the detainees to Afghan custody in the Gulf state of Qatar as one of a series of good-faith measures that, if successful, could lead to talks on Afghanistan's future between militants and the government of Afghan President Hamid Karzai.
The accelerating efforts to set such talks in motion are now a central part of the Obama administration's strategy for leaving behind a modicum of stability as it winds down the U.S. combat mission in Afghanistan.
After over 10 years of war, Washington and its Western allies are announcing their plans to steadily withdraw their troops amid doubts whether the chronically weak, corrupt Afghan government can confront ongoing violence.
Last month, the Taliban made a surprise announcement that it would open a political office in Qatar, suggesting the group may have moderated and would be willing to engage in negotiations that would likely give them government positions or official control over much of their historical southern heartland.
But whether or not the Taliban is truly interested in entertaining authentic political negotiations, or simply wants to recover its prisoners, is unclear.
The impact of the letter received last year on the reconciliation efforts, headed by Obama's special representative for Afghanistan and Pakistan, Marc Grossman, is likewise unclear.
The administration official said the Obama administration is "skeptical" the letter was actually from Mullah Omar. "There's no signature. However, it expresses views consistent with what Taliban interlocutors have told us all along."
U.S. officials say no decision has been made to go ahead with the transfer, but the White House is already facing pushback from members of Congress who warn the Taliban is not a credible negotiating partner and believe transferred detainees could rejoin the fight.
While Congress does not have the power to block the move, the White House might rethink such a risky move if serious bipartisan friction emerged in a presidential election year.