US Defense Secretary Robert Gates confirms that American security firms Xe Services LLC, formerly known as Blackwater, and DynCorp have been operating in Pakistan.
The two firms are operating in private capacities, Gates said on Thursday, adding that the companies were abiding by Pakistani laws.
However, he said that if the Pakistani parliament votes for a ban on the presence of the firms, the US government would comply with it.
Blackwater won notoriety for having gone on a shooting rampage in a heavily trafficked Baghdad intersection in September 2007 killing more than a dozen Iraqi civilians.
Blackwater Worldwide changed its name to Xe Services LLC in February 2009, after it came under international criticism for its disregard for civilian lives.
Two former Blackwater mercenaries have also been charged with the 2009 murder of two Afghan civilians in Kabul.
Asad Durani, former head of Pakistan's Inter-Services Intelligence (ISI), had earlier told Press TV that the notorious firm, Blackwater, was involved in the deadly drone attacks on Pakistani territories, which usually result in civilian casualties.
"I learned somewhere that these people are employed certainly for…the logistic support at the drone bases. That is understandable," Durani said earlier in January.
Gates, meanwhile, said that Washington is considering sharing its Unmanned Aerial Vehicle (UAV) technology with Pakistan.
"These UAVs are useful and we have a budget for them," Gates said in an interview with a privately-run Pakistani television on Thursday.
He claimed that the drones had proved productive in Afghanistan and Iraq.
"We are working together with Pakistan army in this connection," Gates said, adding that discussions were underway with Pakistan military leadership on technical matters in this regard, a Press TV correspondent reported late Thursday.
Defense officials in his delegation later said that the US will provide 12 Shadow drones to Pakistan.
The Shadow drone is about 3.3 meters (11 feet) long and has a wing-span of 4.2 meters (14 feet), with sensors and cameras feeding video images back to operators on the ground.