“Significance is, you kill a leader of one of these groups and it sets them back for a day, a week, a month, depending on who it is, what kind of people are below them…[This] is the right direction,” Mattis said.
Chief Pentagon spokesperson Dana White said the strike also killed other ISIS-K members and “will significantly disrupt the terror group’s plans to expand its presence in Afghanistan.”
ISIS chose Abu Sayed to lead the group as its "third emir" after U.S. and Afghan forces killed previous two emirs, Hafiz Sayed Khan in late July 2016 and Abdul Hasib in late April.
U.S. Forces-Afghanistan Commander General John W. Nicholson called Sayed's death "another success" in the campaign against ISIS-K.
“Abu Sayed is the third ISIS-K emir we have killed in the last year, and we will continue until they are annihilated. There is no safe haven for ISIS-K in Afghanistan,” tweeted Nicholson.
The Iraqi Army declared a “total victory” over ISIS in Mosul on Monday, three years after the group took control of Iraq's second largest city.
Conor Finnegan contributed to this report.