The death brought to 11 the number of NATO service members killed so far this month, with eight of the fatalities being American. So far this year, 40 NATO troops have died in Afghanistan, including 29 Americans.
All foreign combat troops are scheduled to be withdrawn from the country by the end of this year. Casualties have been falling in the US-led military coalition as its forces pull back to allow the Afghan army and police to fight the Taliban insurgency.
The Taliban have launched their annual spring offensive, promising to step up attacks against Afghan security forces in a bid to undermine the Western-backed government as foreign combat troops prepare to withdraw from the country by the end of the year.
On Wednesday, Afghan security forces fought back against a fierce Taliban onslaught by about 800 militants in the southern Helmand province, a Taliban stronghold.
Clashes in Helmand - which was touted as a showcase of a major U.S. military offensive to drive out the militants in 2009 - have been going on for the past four days and have killed dozens of people, including at least 35 civilians.
Wednesday's attacks targeted checkpoints and government buildings in Helmand, in a stark reflection of the challenges facing government troops trying to defend the country against the resilient Islamic militants with diminishing help from the international community.