Top officials in Pakistan's government for years have secretly endorsed the programme and routinely received classified briefings on strikes and casualty counts, 'The Washington Post' reported citing "top-secret" CIA documents and Pakistani diplomatic memos obtained by it.
The story, by well-known investigative journalists, and some of the documents were posted on paper's website, soon after Pakistani Prime Minister Nawaz Sharif flew out of Washington, following a four-day official visit to the US during which he held talks with the American leadership.
"The files describe dozens of drone attacks in Pakistan's tribal region and include maps as well as before-and-after aerial photos of targeted compounds over a four-year stretch from late 2007 to late 2011 in which the campaign intensified dramatically," the report said.
The files expose the explicit nature of a secret arrangement struck between the two countries at a time when neither was willing to publicly acknowledge the existence of the drone programme carried out by the CIA, it said.
"The documents detailed at least 65 strikes in Pakistan and were described as 'talking points' for CIA briefings, which occurred with such regularity that they became a matter of diplomatic routine. The documents are marked 'topsecret' but cleared for release to Pakistan," the report said.
The damaging report, which comes as an embarrassment to Pakistan as Sharif in his talks with President Barack Obama again called for an end to the drone strikes.
"I brought up the issue of drones in our meeting, emphasising the need for an end to such strikes," Sharif told reporters in a joint media appearance with Obama.
According to the report, some of the files describe tense meetings in which senior US officials, including then Secretary of State Hillary Clinton, confront their Pakistani counterparts with US intelligence purporting to show Pakistan's ties to militant groups involved in attacks on American forces, a charge that Islamabad has consistently denied.
In one case, Clinton cited "cell phones and written material from dead bodies that point all fingers" at a militant group based in Pakistan, according to a Pakistani diplomatic cable dated September 20, 2011.
"The US had intelligence proving ISI was involved with these groups," she is cited as saying, referring to Pakistan's Inter-Services Intelligence agency.
In a measure of the antagonism between the two sides, a 2010 memo sent by Pakistan's Ministry of Foreign Affairs to its embassy in Washington outlined a plan to undermine the CIA, the report said.
"Kindly find enclosed a list of 36 US citizens who are (believed) to be CIA special agents and would be visiting Pakistan for some special task," said the memo, signed by an official listed as the country's director general for Americas.
"Kindly do not repeat nor issue visas to the same," the Post quoted the secret Pakistani memo as saying.
The report said, several documents refer to a direct Pakistani role in the selection of targets.
A 2010 entry, for example, describes hitting a location "at the request of your government".
Another document from that year refers to a "network of locations associated with a joint CIA-ISI targeting effort," the report said.
According to the daily, the CIA along with other things shared maps and photographs of drone operations in Pakistan that have not previously been shown publicly.
"The maps contain simplistic illustrations, including orange flame emblems to mark locations of strikes. The photos show before-and-after scenes of walled compounds and vehicles destroyed by Hellfire missiles, some marked with arrows to identify bodies amid the rubble," the report said.
The documents indicate that these and other materials were routinely relayed "by bag" to senior officials in Islamabad, it said.
The report, said in one case, deputy director of the CIA Michael J Morell, indicated that the CIA was prepared to share credit with the Pakistanis if the agency could confirm that it had killed Ilyas Kashmiri, an Al Qaeda operative suspected of ties to plots against India.
The agency would do it, "so that the negative views about Pakistan in the US decision and opinion making circles are mitigated," according to a diplomatic memo quoted in the report.
Image: A Jamaat-e-Islami supporter flashes the victory sign in front of an image of drone, during a rally against drone attacks
Photographs: Athar Hussain/Reuters
Obama wows Sharif with Pak memories: I can cook daal and keema
Obama asks Sharif: Why has trial of 26/11 accused not started?
SHOCKING: '1.4 crore Indians live like slaves'
Obama, Sharif talk terror; no promise of ending drone strikes
Limits to India's engagement with China