Eight American soldiers and two Afghan troops have been killed in the deadliest attack on coalition troops for more than a year.
A NATO statement said military outposts in Nuristan province were attacked in the remote east of Afghanistan on Saturday.
The Taliban said it carried out the attack which lasted several hours.
US jets carried out air strikes in response.
The BBC reports it was the worst loss that coalition troops have suffered since August 2008, when 10 French troops were killed in an ambush in Kabul province.