OFAC acts under Presidential wartime and national emergency powers, as well as authority granted by specific legislation, to impose controls on transactions and to freeze assets under U.S. jurisdiction. Many of the sanctions are based on United Nations and other international mandates; therefore, they are multilateral in scope, and involve close cooperation with allied governments. Other sanctions are specific to the interests of the United States. OFAC has been delegated responsibility by the Secretary of the Treasury for developing, promulgating, and administering U.S. sanctions programs.