Afghanistan's government said on Sunday that its investigations have found NATO killed 65 civilians, many of them children, during recent operations in a remote northeastern militant stronghold.
The death toll from several days of operations in Kunar province comprised 21 boys, 19 girls, 10 women and 15 adult males, President Hamid Karzai's office said in a statement quoting an official delegation.
Karzai has now ordered his security chiefs to "discuss the issue" with international forces, his office said, without providing further details.
In response, a spokesman for the NATO-led International Security Assistance Force (ISAF), Lieutenant Colonel John Dorrian, said it was "deeply sorry... for any civilian casualties that have occurred as part of this operation."
But he disputed the death toll, saying ISAF's assessment only found five to seven civilians "may have injured." Investigations were continuing, he added.
Karzai appointed the delegation last week after he first accused international forces of killing civilians in an operation targeting insurgents -- a highly sensitive issue in Afghanistan.
Karzai says such incidents erode support for his Western-backed administration.
There are about 140,000 foreign troops, the bulk of them American, deployed in Afghanistan to help Kabul defeat the Taliban, but civilian casualties have exacerbated longstanding tensions between the government and its Western allies.
On Thursday, NATO also said it was investigating allegations that fire from one of its planes killed five civilians in Kapisa province, north-east of Kabul.
Local villagers had alleged the men were civilians hunting in the mountains of Alasai district when they were attacked by NATO planes, provincial police chief Abdul Hamid Arkin told AFP.