Mokhtar Belmokhtar and other fighters were killed in the operation in the eastern city of Ajdabiya, a statement from Libya's government said.
However, there have been incorrect reports of his death in the past.
The Pentagon has confirmed Belmokhtar was the target of a strike but has not said if he was killed.
"We are continuing to assess the results of the operation and will provide more details as appropriate," said Pentagon Spokesman Steve Warren.