The U.S.-led military coalition says the service member died Sunday after a direct-fire insurgent assault. It did not provide any other details.
The death brings the number of international forces killed this month in Afghanistan to 20.
May has been the deadliest month this year for international troops in Afghanistan, but casualties are down over previous years as foreign forces pull back and allow Afghan security forces to take the lead before the coalition ends its mission next year.
Last May, a total of 44 NATO troops died in Afghanistan.
The coalition also said a car bomb hit a NATO convoy early Monday in the country's west, but there were no military casualties.