A public international organization is any organization designated as such by Executive order under the International Organizations Immunities Act, 22 U.S.C. § 288, or any other organization that the President so designates.
Currently, public international organizations include entities such as the United Nations, the World Bank, the International Monetary Fund, the World Intellectual Property Organization, the World Trade Organization, the OECD, the Organization of American States, and numerous others.
