The unit is under day-to-day operational control of the civilian State Department Bureau of Counterterrorism (S/CT).

The unit's primary mission is its role as a senior member of the Foreign Emergency Support Team.

Little is known of the unit, which is responsible for supporting Department of State counterterrorism policies, plans, programs, operations, exercises, training, and activities both in the National Capital Region and around the world.

[3] ARCU primarily supports the Coordinator for Counterterrorism and serves to assist diplomats, advising, assisting, and assessing the U.S. whole-of-government national counterterrorism response to overseas terrorist incidents while helping to synchronize American Diplomatic, Information, Military, Economic, Financial, Intelligence and Law Enforcement (DIMEFIL) assets in response.

The unit works to forge partnerships with various intelligence agencies, non-state actors, multilateral organizations, and foreign governments to advance counterterrorism objectives, assisting in developing coordinated strategies to defeat terrorists abroad and securing the cooperation of international partners.