Pentagon officials did not identify the leader of say whether the strike was successful.
A senior defense official said the strike did not target Ahmad Umar, who took over as the top leader of al-Shabab when its previous leader, Ahmed Abdi Godane, was killed in a U.S. airstrike in Somalia on Sept. 1. The official spoke on condition of anonymity because he was not authorized to discuss details of the attack by name.
In a brief written statement the Pentagon said the airstrike took place Monday in the vicinity of Saakow, Somalia. It provided no details, beyond saying it did not believe the attack caused any civilian or bystander casualties.
Al-Shabab is an ultra-conservative Islamic extremist group that is linked to Al Qaeda. The group wants to run Somalia under its interpretation of Shariah law.
Umar, the top al-Shabab leader, goes by several aliases, but intelligence officials in Somalia say they know him as Sheikh Mahad Abdikarim, a militant who once governed Somalia's Bakool region on behalf of al-Shabab.
In 2012 the U.S. offered a $3 million reward for information leading to Umar's arrest. At the time Umar was reported to be al-Shabab's intelligence chief.
