The US military informed the families of the 11 marines, the sailor and the soldier killed in the blast during the chaotic US withdrawal from Afghanistan.
About 170 Afghans were also killed in the bombing outside Hamid Karzai International Airport on 26 August 2021.
Family members of the US personnel shared the information in a private messaging chat group, according to one marine’s mother.
The account from the families was confirmed by US officials, who spoke to the Associated Press on the condition of anonymity.
The IS leader, whose identity has not yet been released, was killed in southern Afghanistan in early April.
The Taliban were conducting a series of operations against the Islamic State group, according to one of the officials.
At the time, the Taliban were not aware of the identity of the person they killed, the official added.