Citizens of the United States, Canada, Mexico and Bermuda are now required to present a passport to enter the United States

when arriving by air from any part of the Western Hemisphere. According to the U.S. Department of Homeland Security, "more than 90 percent of U.S. citizens, 97 percent of Canadians, and virtually 100 percent of Mexicans and Bermudans flying to the United States over the past week arrived with passports."