A U.S. service member died as a result of injuries sustained Tuesday during combat operations against the Islamic State in Afghanistan, the U.S. military said.

U.S. advisers are accompanying Afghan forces during operations against Islamic State militants in Nangahar province, where extremists have attempted to establish a stronghold.

“The service member was killed conducting operations with Afghan forces when the patrol triggered an improvised explosive device,” according to a U.S. military statement.

The serviceman, who the Pentagon has not yet identified, was killed while conducting a counterterrorism mission in partnership with Afghan forces, the Pentagon said.

There are fewer than 10,000 U.S. troops in Afghanistan. Their role is to advise and assist Afghan security forces and also conduct counterterrorism operations.

The White House has said the remaining forces in Afghanistan are not conventional combat forces, but Pentagon press secretary Peter Cook acknowledged the forces are still in “harm’s way.”

“This was a combat situation,” Cook said.

The casualty would be the third U.S. combat death in Afghanistan this year, according to iCasualties.org, which tracks combat deaths.