The new round of strikes follows the deadly December ambush that killed two U.S. soldiers and one American civilian interpreter.

The destroyer departed from Naval Station Norfolk, Virginia, for what the service called a scheduled deployment.

The U.S. has dispatched a small team of military officers to Nigeria, the general in charge of U.S. Africa Command told reporters in a briefing Tuesday.

The Pentagon eventually wants to field swarms of low-cost, one-way attack drones that cost just a few thousand dollars apiece.