The Office of Foreign Assets Control ("OFAC") of the US Department of the Treasury administers and enforces economic and trade sanctions based on US foreign policy and national security goals against targeted foreign countries and regimes, terrorists, international narcotics traffickers, those engaged in activities related to the proliferation of weapons of mass destruction, and other threats to the national security, foreign policy or economy of the United​ States.
OFAC publishes lists of individuals and companies owned or controlled by, or acting for or on behalf of, targeted countries. It also lists individuals, groups, and entities, such as terrorists and narcotics traffickers designated under programs that are not country-specific.
OFAC provides significant guidance at this link: https://home.treasury.gov/policy-issues/office-of-foreign-assets-control-sanctions-programs-and-information