By Nick Paton Walsh in Kabul, with reporting from Barbara Starr, Richard Allen Greene, Shaan Khan, Pam Benson and Joe Sterling
The Taliban in Afghanistan depend on Pakistan for support, even though they do not necessarily welcome it, a secret NATO report says, according to a journalist who has read it.
"It is a marriage of convenience," Times of London reporter Jerome Starkey said Wednesday, citing the report. The Taliban see Pakistan as manipulative, but they see no alternative to accepting its support, he said.
The Taliban are absolutely confident of victory, he said the report found, based on 27,000 interviews with over 4,000 detainees ranging from senior Taliban commanders to Afghan civilians.
They also include mid- and low-level Taliban, al Qaeda, and foreign fighters, he said.
The leaked NATO document revives the longstanding accusation that elements in Pakistan's Inter Services Intelligence agency are aiding the insurgency in Afghanistan.
It says the ISI knows the whereabouts of all senior Taliban commanders, Starkey said.
NATO downplayed the importance of the report Wednesday, after it was leaked, while Pakistan rejected key conclusions entirely.
CNN has not seen the document.
A spokesman for NATO's International Security Assistance Force in Afghanistan said Wednesday not to read too much into it.
The classified report is based on the "opinions or ideals" of Taliban detainees - and represented only their opinions, not the actual progress of NATO against the Taliban, Lt. Col. Jimmie E. Cummings said.
He said it was "extremely important not to draw conclusions based on Taliban comments or musings" and that the report "should not be used as any interpretation of campaign progress" against the insurgency.
Pakistan firmly dismissed the accusation it was helping the Taliban across the border.
"We are committed to non-interference in Afghanistan," Pakistan Foreign Office spokesman Abdul Basit said Wednesday.
"This is frivolous, to put it mildly," Basit said.
"Pakistan has suffered enormously because of the long conflict in Afghanistan. A stable and peaceful Afghanistan is in our own interest and we are very much cognizant of this," he said.
The alleged contents of the report would be consistent with international concerns that elements within Pakistan's powerful ISI agency are helping the Taliban in Afghanistan.
The U.S. intelligence community said Tuesday that Afghanistan's insurgents remain "resilient" and senior Taliban leaders "enjoy safe haven in Pakistan."
The annual threat assessment compiled by all the various American intelligence agencies said Taliban-led insurgents have "lost ground in some areas," but mainly where NATO-led "surge forces are concentrated."
A U.S. official told CNN the ISAF report included a summary of comments from "some of the most motivated and ruthless insurgents that are trying to boost insurgent morale."
"Some of the stuff there you couldn't even deem 'intel.' It's just comments," said the official, referring to intelligence.
Starkey, the Times journalist, said the report said it should be treated as informational and not necessarily analytical.
The official described the report as "relatively new" and "an internal document for our use that's not meant to be distributed."
The official emphasized that it did not represent the opinions of ISAF.
The official is not authorized to discuss contents of the report on the record with the media and asked not to be named.
The official declined to say whether the report was seen by top NATO commanders, including the ISAF commander, Gen. John Allen, or whether it was written by military or civilian ISAF personnel.
The leak comes as Afghan President Hamid Karzai's government appears to be moving slowly towards talks with the Taliban.
Karzai's government recently dropped its opposition to the Taliban establishing an office in the Gulf state of Qatar to facilitate talks.
And it may be opening a separate channel to talk to the insurgency.
The Afghan government hopes to hold talks with Taliban representatives in Saudi Arabia in the coming weeks, a senior Afghan official said Tuesday, in a move that threatens to cloud already fragile steps to negotiate an end to the United States' longest war.
The senior official, speaking anonymously as he was discussing sensitive diplomatic issues, said there were plans for a meeting between insurgents and Afghan officials in Saudi Arabia. Yet, he added, the plans were at such an early stage that it was not clear who - including American officials - would attend or when any talks would be held.
The United States has acknowledged that it has held discussions about the opening of a Taliban office in Doha, Qatar, as well as the possibility of transferring some Taliban prisoners held at Guantanamo Bay as part of American support for Afghan reconciliation efforts.