The Pentagon identified the U.S. service member killed in action in Helmand Province, Afghanistan, on Thursday as Sgt. James A. Slape.

The 23-year-old from Morehead City, N.C., died of injuries from an improvised explosive device, the Pentagon said in a statement. Slape was assigned to 60th Troop Command, North Carolina Army National Guard, Washington, N.C.

Slape was posthumously promoted to sergeant.

The incident is under investigation, the statement said.

"We mourn and honor the sacrifice of our service member,” said Gen. Scott Miller, commander of Resolute Support and U.S. Forces-Afghanistan, in a statement Thursday. “We remain committed.”

Slape’s death is the eighth American casualty in Afghanistan in 2018 — seven were killed in action and one service member died under noncombat conditions. The Afghanistan War turns 17-years-old on Sunday.