The United States operates border preclearance facilities at a number of ports and [https://www.espatial.com/articles/preclearance-map airports] in foreign countries. They are staffed and operated by U.S. Customs and Border Protection officers. Travelers pass through Immigration and Customs, Public Health, and Department of Agriculture inspections before boarding their aircraft, ship or train. This process is intended to streamline border procedures, to reduce congestion at ports of entry, and to facilitate travel between the preclearance location and U.S. airports unequipped to handle international travellers.