Pakistan's prime minister has warned that his country's dealings with the United States will no longer be “business as usual” in the wake of the NATO airstrike on Saturday that killed 24 Pakistani soldiers.

Yousuf Raza Gilani told CNN on Monday that the bilateral relationship must be based on “mutual respect and mutual interest,” and he said that does not currently exist. Pakistan's army spokesman, Major General Athar Abbas, said the attack “could have serious consequences” for the level of Pakistan's cooperation with the United States. The general denied suggestions by NATO and Afghan officials that the attack had been provoked by fire from a Pakistani army base. He accused the officials of making excuses.

In response to the attack, Pakistan has shut down NATO supply routes into Afghanistan and ordered the evacuation of a U.S. air base in southwestern Baluchistan province.

At the White House, U.S. President Barack Obama called the attack a “tragedy.” A spokesman said the administration is taking the matter very seriously and that there will be separate investigations by NATO and the U.S. Central Command. He said the United States and Pakistan have “an important cooperative relationship that is also very complicated.”

At the U.S. State Department, a spokesman told reporters the relationship was a “vitally important” one that he said has “weathered significant setbacks” in the past. He said both countries need to find a way to move forward. He also revealed that Pakistan is considering boycotting next week's conference in Bonn, Germany, focusing on efforts to stabilize Afghanistan. He urged Pakistan to attend.