An insurgent rocket attack killed one NATO soldier and injured another while they were on patrol in central Afghanistan on Thursday, the Western alliance said.
NATO soldiers and militants exchanged small arms fire, and air support was used against the insurgents, NATO's International Security Assistance Force said in a statement.
The nationalities of the soldiers were not released.
Insurgents have stepped up attacks against Western and Afghan security forces this year, the deadliest in Afghanistan since the fall of the Taliban regime in 2001. More than 3,700 people have died in insurgency-related violence.
Attacks have fallen off in recent weeks as an early winter has brought snow to Afghanistan's mountains. NATO officials also say that offensive operations the last couple months have reduced insurgents' capabilities.
Thursday's death was the first of a Western soldier in more than two weeks.