Washington ? After reviewing a disputed airstrike on a village in Afghanistan, U.S. officials have concluded that the civilian death toll was far lower than claimed by the Afghan government and the U.N., three U.S. defense officials said Thursday.

Two of the officials, who spoke on condition of anonymity because the results of the review have not been announced publicly, said Afghan officials have been given the findings, which say 25 militants were killed, plus five civilians. Afghan officials have said that between 76 and 90 civilians were killed.

Also, the U.S. government is pressing for a joint U.S.-Afghan probe in hopes of reaching a common conclusion about an incident that stirred outrage in Afghanistan and frustration among U.S. officials, one official said.

It was not clear Thursday whether the Afghan government accepted the findings of the U.S. review or whether a joint probe would go forward. Details of how the U.S. review was conducted were not immediately available.

In the days following the clash in western Afghanistan, the government of President Hamid Karzai issued a sharp rebuke of the United States, saying the incident showed the need for tighter regulation of U.S. military operations.

Afghanistan’s Council of Ministers ordered the ministries of defense and foreign affairs to open negotiations with the U.S. and NATO over the use of airstrikes, house searches and the detentions of Afghan civilians. It also called for a “status of forces” agreement to regulate the troops’ presence.

The disputed attack was launched during a raid on a compound identified as being used by a top Taliban commander. The U.S. military publicly announced afterward that 25 militants had been killed, plus, unintentionally, five civilians.

Earlier this week a United Nations human rights team said it had found “convincing evidence” to support claims that about 90 civilians were killed, including 60 children.

The U.S. military in Afghanistan said the operation was led by Afghan National Army commandos, with support from U.S. Special Operations forces. It said that in addition to the fatalities, five militants were detained. Troops also seized ammunition, grenades, rifles and bomb-making materials.

At the Pentagon on Thursday, Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, said he was not aware of the result of the U.S. review of the disputed airstrike.

“We work exceptionally hard to minimize any collateral damage,” Mullen said, referring to unintended casualties. “Zero collateral damage is the goal. We know that when collateral damage occurs, that it really does set us back, so we worked exceptionally hard to make sure it doesn’t happen.”

The U.S. military makes frequent use of air power in both Iraq and Afghanistan but has drawn more highly publicized accusations of civilian deaths in Afghanistan. Asked about this, Mullen said he has made clear to commanders the importance of avoiding civilian casualties.

The Joint Chiefs chairman announced that he met in secret on Tuesday with his Pakistani counterpart, Gen. Ashfaq Kayani, to discuss efforts to slow the infiltration of militants from Pakistan into Afghanistan.

Mullen declined to give details about discussions with Kayani, but said the Pakistani general has been moving in the right direction with his efforts to combat an increasingly emboldened insurgency.