Department of State
The United States has imposed restrictions on activities with Iran under various legal authorities since 1979, following the seizure of the U.S. Embassy in Tehran.
The Department of State's Office of Economic Sanctions Policy and Implementation is responsible for enforcing and implementing a number of U.S. sanctions programs that restrict access to the United States for companies that engage in certain commercial activities in Iran.
Department of Treasury
The Department of Treasury also plays a primary role in enforcing sanctions against Iran. For more information on the Department of Treasury's sanctions implementation, please visit their website.