FBI Director Kash Patel said the suspect was plotting "a violent attack."
The airstrikes targeting militants affiliated with the Islamic State in northwestern Nigeria are a major escalation of an offensive that Nigeria's overstretched military has struggled with for years.
President Trump said in a post on his social media platform Thursday that he launched a "powerful and deadly strike" on ISIS terrorists in Nigeria, whom he claimed have been "targeting and viciously killing, primarily, innocent Christians."
The strikes are in retaliation for the deaths of three Americans in Palmyra, Syria, on Saturday.
A U.S. airstrike in western Iraq on Thursday killed the ISIS' chief of global operations who also served as ISIS' second in command, known as "Abu Khadijah."
The man, a former Iraqi refugee and legal permanent resident of Richmond, Texas, provided support for years. He's expected to be sentenced this summer.