The Delta Force (1st Special Forces Operational Detachment-Delta), is a U.S. Army unit used for hostage rescue and counterterrorism, as well as direct action and reconnaissance against high value targets. While 1st SFOD-D is administratively supported by USASOC, it falls under the operational control of the Joint Special Operations Command. Delta Force and its Navy counterpart, SEAL Team Six, are the United States military's primary counter-terrorism units. It is often referred to in the U.S.