Major General Shaukat Sultan said Pakistani Forces were co-operating with US-led coalition troops who are on the other side of the porous frontier, but "it is a co-operation in terms of intelligence sharing."
"It is not in terms of inviting their (coalition) fire onto our territory", said Sultan.
Pakistan is a key ally in Washington's so-called war on terror, and has launched its own anti-militant operations near the border, but is highly sensitive to claims that its forces are in any way under US control.
It has repeatedly denied reports that US Central Intelligence Agency (CIA) operatives and special forces are based in the tribal regions close to Afghanistan.
Colonel Crawford told reporters in Washington that Pakistani forward observers were directing US firepower against suspected hideouts inside Pakistan.
"Something I think you'll find interesting is the Pakistanis have adjusted our artillery fire into the Pakistani side of the border to go after any coalition militias", said Colonel Crawford, adding that the co-operation was a "huge step forward."
The US military had supplied Pakistan with radios to improve cross-border communications, while liaison officers were now posted in their respective headquarters and commanders near the border meet to work out issues, he said.
Pakistani tribal areas on the border have long been suspected of being a sanctuary for hundreds of Al-Qaeda and Taleban militants who fled the post-9/11 US military campaign in Afghanistan.