All persons including citizens of the United States traveling by air between the U.S., Canada, Mexico, the Caribbean and Bermuda will have to present a passport, Merchant Mariner Document (presented by U.S. citizen merchant mariners traveling on official business) or NEXUS Card, NEXUS enrollment is limited to citizens of the United States and Canada, and lawful permanent residents of the United States and Canada. Children will be required to present their own passport. Beginning June 1, 2009, ages 16 and older will be required to present documents from one of the options below when entering the United States at land or sea ports of entry. Children under may present an original or copy of his or her birth certificate, a Consular Report of Birth Abroad, or a Naturalization Certificate.