The Pakistani military has given clearance for commanders in areas along the border with Afghanistan to return fire if they are attacked.
The move comes in response to a NATO attack on Pakistani military posts near the Afghan border on November 26 that killed 24 Pakistani soldiers.
The deaths of the soliders sparked widespread outrage in Pakistan against NATO and the United States, but also raised questions about the failure of the Pakistani military to respond to attacks that Pakistani authorities say lasted some two hours.
A statement from the Pakistani military released on December 2 blamed a "breakdown of communication" and confusion at "various levels" for the lack of response.
Pakistan's chief of army staff, Ashfaq Kayani, said in a message to military commanders that "in case of attack, you have complete liberty to respond forcefully using all available resources, you do not need permission for this."
U.S. and NATO officials have expressed their condolences to the families of those killed in the attack but stopped short of giving official apologies until an investigation into the incident is completed.
A report in the "Wall Street Journal"
quoted unnamed U.S. officials who said initial debriefings suggested the Pakistani side in a joint Afghan-Pakistani-NATO monitoring system for the border region had given the go-ahead for the air strike, unaware that their own forces were in the area.
compiled from agency reports