The U.S. State Department said on Thursday that Mullah Mohammed Omar, the leader of Taliban, does not qualify to play a constructive role in the future of Afghanistan.

State Department spokesman Philip Crowley said that the United States holds the view that Mullah Omar is responsible for the 9/11 attack and supports Osama bin Laden.

"He had many opportunities during the 90s and even after 9/11 to disassociate himself from Osama bin Laden. He chose not to," said Crowley.

"Thus he will not meet the criteria" to join the reconciliation process, he said, referring to the three conditions of renouncing violence, severing ties with al-Qaida and adhering to laws of Afghanistan.

"We have great skepticism that Mullah (Omar) is going to be one of those people who takes advantage of this process," Crowley said.

Despite his blunt denial of Omar's potential role in Afghanistan's future, it seems unlikely that a reconciliation could be achieved without bringing in Taliban and its leadership.

Afghanistan's President Hamid Karzai has repeatedly called on Taliban leadership to give up militancy and join the peace process.

Reports here said the Obama administration, deeming the war in Afghanistan could not be won by military means alone, recently appeared open to talks with Taliban rather than resisting them.

A senior NATO official reportedly said the alliance was giving "safe passage" for Taliban senior leaders to travel to the Afghan capital of Kabul for talks with the Afghan government.

In addition, NATO Secretary General Anders Fogh Rasmussen said on Thursday that the alliance was ready to facilitate the Afghan government's outreach to the Taliban militants.?