Expo Unit Home Expo Unit Home About Us Expositions Hosting the World’s Fair Past U.S. Pavilions External Links HomeBureaus & Offices > Office of Policy, Planning, and Resources ...Expo Unit hide Expo Unit Subscribe Our Mission The Department of State is responsible for U.S. participation in international exhibitions. The Department’s Expo Unit in the Office of the Under Secretary for Public Diplomacy and Public Affairs, Office of Policy, Planning, and Resources manages U.S. engagement with the Bureau of International Expositions (BIE), organizes U.S. participation at overseas Expos (also known as World’s Fairs), and mobilizes international support for U.S. candidacies to host Expos.