The Western Hemisphere Travel Initiative (WHTI) is a law of the United States that requires all travelers to show a valid passport or other approved secure document when traveling to the U.S. from areas within the Western Hemisphere. The purpose, according to the U.S. Department of State and U.S. Department of Homeland Security, is to strengthen border security and facilitate entry into the United States for both legitimate U.S. citizens and foreign visitors. The initiative is an outcome of the Intelligence Reform and Terrorism Prevention Act. The Western Hemisphere Travel Initiative was also implemented to prevent false documents.