US Friendly Fire Report 'Unacceptable' The Pakistani military roundly rejected a U.S. investigative report into the November friendly fire incident that resulted in the deaths of 24 Pakistani soldiers, saying the implication that Pakistan deserves any blame is "unjustified and unacceptable." "Pakistan does not agree with several portions and findings of the Investigation Report as these are factually not correct," the Pakistani military said in a statement. The fundamental cause of the incident... was the failure of U.S. / ISAF (International Security Assistance Force) to share its near-border operation with Pakistan on any level. According to the U.S. investigative report, in late November a ground force of 120 Afghan and American soldiers were moving through rugged terrain near the Afghanistan/Pakistan border when they began taking fire from a ridgeline in Pakistan. The ground commander in the area had been told there were no Pakistani military forces in the area and ordered air strikes by helicopter on the ridgeline, the report said. Those airstrikes, however, struck two Pakistani military outposts, killing two dozen Pakistani soldiers. The outposts were only three months old and had not been marked on American maps. The U.S. report identified several instances of failures of communication and other mistakes that led to the friendly fire incident, but ultimately said the airstrikes were justified. U.S. and NATO officials offered their "deepest regrets" over the incident, but never officially apologized. US Takes Some Blame in Deadly Pakistan Friendly Fire Incident In its response to the U.S. report, the Pakistani military said their soldiers died because the U.S. military did not tell them about their near-border operations, which "violated all mutually agreed procedures with Pakistan... put in place to avert such uncalled for actions." "This obviously was a major omission," the statement said. U.S. Air Force Brig. Gen. Stephen Clark, who led the U.S. investigation, said in December a U.S. officer at the Border Coordination Center did not share the exact location of the U.S.-led unit on purpose and was told to be vague in reports to the Pakistani military. In previous instances, U.S.-led missions had been compromised after specific information had been given to Pakistani forces, Clark said. Compounding the problem, the officer was providing the Pakistanis with wrong information because mapping software had been incorrectly loaded on his computer. The Pakistani response also said the U.S. had violated its own mandate by initiating an "unprovoked engagement" outside Afghanistan's borders. Pentagon spokesperson Capt. John Kirby told ABC News today that the U.S. stands by Clark's investigation and said that characterizing American actions as "unprovoked" is "simply false." "We've said that before many times," Kirby said. We've also said... that there were errors made on both sides. Kirby noted that Pakistani officials had declined to participate in Clark's investigation, which could have made it "more thorough." A Pakistani military account of the incident provided in December to the U.S. Congress by Pakistan's lobbying firm in Washington, D.C., differs greatly from the American account. It claims a NATO helicopter mistakenly began firing on a Pakistani outpost called Volcano after it had been given incorrect coordinates for the incoming fire. When another outpost, Boulder, attempted to signal the helicopters using illuminating rounds, the helicopters then turned and attacked it as well. "Any allegation that the NATO troops thought that they were firing on insurgents when they attacked the Volcano and Boulder observation posts is baseless," the Pakistani document says. NATO was aware that the bases were there when they fired on them. NATO troops are also well aware that terrorists seeking refuge in mountainous areas install themselves in ravines and deep valleys which provide cover from aerial attacks -- not in plain sight on the top of a mountain. ABC News' Nick Schifrin contributed to this report.