The United States rejected Monday the findings of a Pakistani probe into NATO air strikes that killed 24 Pakistani soldiers in late November, saying the investigation ignored the fact that "mistakes" were made on both sides.

At a press briefing, Pentagon spokesman John Kirby said the Pakistani army had officially delivered during the weekend a copy of the report conducted by Islamabad on the November 26 strikes against a Pakistani border post.

"The statement that this was an unprovoked attack by US forces is simply false," said Navy Captain Kirby. "It was not an unprovoked attack," he said. "There were errors made by both sides here."

Underscoring its criticism of the NATO force in Afghanistan, the Pakistani military rejected Monday US efforts to apportion some of the blame to Pakistan as "unwarranted and unacceptable."

Kirby said the Pentagon was "100 percent" behind the findings of the investigation report released last month by the US military.

That report, while acknowledging some responsibility in the bombing of one or two Pakistani border posts, argued that NATO troops had fired in "self-defense" after being shot at by "heavy weapons and mortar" from an "unidentified" source in a remote area infiltrated by Taliban organizations.

Captain Kirby regretted that Islamabad refused to participate in the investigation initiated by the US military. He called on Pakistan to reopen supply routes for NATO troops in Afghanistan, which were closed after the bombing.

"We want to get past all this and we want to build a good cooperative relationship with the Pakistani military," he said.

The crisis in US-Pakistani relations has been overshadowed by a stand-off between the courts and the civilian government that analysts believe could force early elections in Pakistan within months.