One US soldier has been killed and four others wounded during a "combat engagement” in eastern Nangarhar province on Monday, the US military said in a statement on Tuesday.
The incident took place in the Achin district of Nangarhar. Two of the wounded service members are being treated at a medical facility and are in stable condition, according to the statement.
Achin is among the most insecure districts of the province in which mostly Daesh insurgents have active since the start of 2015.
The Taliban and Daesh have frequently fought each other in Nangarhar and both have been targeted by sustained US air strikes.
There are currently about 14,000 US troops in Afghanistan. Under President Donald Trump's South Asia strategy, US troops are allowed to accompany Afghan forces at the battalion level, potentially putting them at greater risk, according to reports.