A U.S. service member who died this week in Afghanistan was the first American military member killed in that country fighting ISIS.
"This is the first U.S. service member killed in Afghanistan fighting Daesh," Army Brig. Gen. Charles Cleveland, deputy chief of staff of communications for Resolute Support, confirmed to The Hill on Wednesday, using a derogatory Arabic name for the Islamic State in Iraq and Syria.
The service member, whose identity will be released after kin are notified, was killed Tuesday while on a patrol with Afghan forces in the eastern province of Nangarhar. The patrol was part of the mission against ISIS in Afghanistan.
The service member was killed by an improvised explosive device, according to officials.
While the Pentagon refrained from calling it "combat," press secretary Peter Cook called it a "combat situation."
The U.S. formally ended its "combat mission" in December 2014, but officials acknowledge that U.S. special operators are still accompanying Afghan commandos on 10 percent of their missions.
"On average, we probably have somebody out every night or every other night, some place in the country," Cleveland said in August.
There are currently 9,800 U.S. troops in Afghanistan.
There are an estimated 1,200 to 1,300 ISIS fighters in Afghanistan, primarily in three to four districts in Nangarhar, where they are trying to establish a caliphate, the top U.S. commander in Afghanistan said last month.
That was down from as many as nine to 10 districts in Nangarhar last year, Gen. John Nicholson told reporters.
Afghan commandos, accompanied by U.S. forces, began conducting counter-ISIS operations in Nangarhar in late July, killing 12 ISIS leaders and taking out roughly 25 percent of its fighters, he said.
ISIS fighters in Afghanistan are primarily Pakistani Pashtun who were previously Taliban Pakistan, or TTP, and changed alliance to ISIS's Afghanistan affiliate, known as the Islamic State — Khorasan, or ISK. Some ISIS fighters were formerly from the Islamic Movement of Uzbekistan, he said.
ISIS's parent organization in Syria has provided some financial assistance and guidance to its nascent affiliate in Afghanistan, he added.