On Monday, Islamabad turned back about 300 cargo trucks carrying fuel and other supplies for NATO forces in Afghanistan ostensibly in response to a NATO-led airstrike that killed 24 Pakistani soldiers.
NATO Secretary-General Anders Fogh Rasmussen called the incident "tragic," noting the alliance would work with Pakistani authorities to set up a joint investigation into the incident.
Islamabad said the attack by NATO forces was unprovoked. The government said the assaults continued even after Pakistan made clear to the coalition through all possible channels an official checkpoint was under attack.
Pakistani Prime Minister Syed Yousuf Raza Gilani said in a Monday interview with CNN that there would be "no more business as usual" with Washington following the incident.
Ties between the United States and Pakistan are at lows following the May raid in Pakistan by U.S. forces that killed al-Qaida leader Osama bin Laden.
Taliban spokesman Ihsanullah Ihsan told the cable news network that Pakistan should respond to the NATO strike.
Rasmussen said the incident was regrettable but the alliance committed to the overall mission in the region.
"NATO remains strongly committed to work with Pakistan to improve cooperation to avoid such tragedies in the future," he said.
Notable deaths of 2014 [PHOTOS]