The head of Daesh in Afghanistan, Abu Sayed, was killed in a strike on the group's headquarters in Kunar province earlier this week, the Pentagon said on Friday.
Pentagon spokeswoman Dana White said in a statement that other members of Daesh were also killed in the strike on Tuesday.
US Defense Secretary Jim Mattis told reporters, "The significance is you kill a leader of one of these groups and it sets them back ... it is obviously a victory on our side in terms of setting them back, it is the right direction."
Sayed is the third Daesh leader in Afghanistan to be killed since July 2016.
Former leader killed
Former leader Abdul Hasib was killed in a joint US and Afghan operation on April 27 in the eastern province of Nangarhar. Hasib's predecessor Hafiz Saeed Khan died in a US drone strike in 2016.
The local affiliate of Daesh has been active since 2015, fighting the Taliban and Afghan and US forces.
General John Nicholson, the top US commander in Afghanistan, has vowed to defeat Daesh there this year.