President Karzai says civilian casualties undermine the fight against insurgents
Afghan President Hamid Karzai has called on the US to halt air strikes in his country, following an attack that reportedly killed scores of civilians.
Mr Karzai, who is in Washington, told CNN air strikes were "not acceptable".
Afghan officials say more than 100 civilians died when US jets attacked targets in the western Farah province.
The incident overshadowed a summit on Wednesday between the President Barack Obama, Mr Karzai, and his Pakistani counterpart Asif Ali Zardari.
"We demand an end to these operations... an end to air strikes," Mr Karzai told CNN.
He said the deaths were "definitely" the result of US air strikes and not Taleban militants, as some US military officials had suggested.
Afghan and US officials are investigating how many civilians died
"We believe strongly that air strikes are not an effective way of fighting terrorism, that air strikes rather cause civilian casualties and does not do good for the US, does not do good for Afghanistan," he said.
US military and Afghan officials are investigating the attacks and trying to ascertain how many of those killed were insurgents.
The US says the Afghan estimate is "grossly exaggerated" but has not released its own figures.
At their summit in Washington, the US, Afghan and Pakistani presidents discussed their joint operation against al-Qaeda and the Taleban.
Pakistani forces are currently engaged in fierce fighting with Taleban insurgents in the north-west of the country.
US Secretary of State Hillary Clinton said she "deeply, deeply" regretted the deaths, adding that the US would work hard to avoid such "loss of innocent life".