"Burden of proof" is discussed in the Immigration and Nationality Act section 291. Under current heightened security measures in effect at all ports-of-entry, including those at land border crossing points, each person wishing to enter the United States is responsible for having sufficient documentation to establish identity and citizenship.

NOTE: CBP heightened security now requires that each person may have to present identification that has a photograph attached.

Entry of Citizens of Canada
Citizens of Canada are exempt from the visa and passport requirement of Immigration and Nationality Act (section 212(a)(7).) To enter the United States, a Canadian citizen must be able to establish both identity and citizenship. Documents that may establish citizenship are:

• Birth certificate
• Citizenship certificate
• Passport.

Although a CBP officer may accept an oral declaration of citizenship, it is recommended that a Canadian citizen carry a document that establishes citizenship. Under current procedures, all travelers may be required to present photo-identification.

NOTE: A Canadian citizen arriving from outside the Western Hemisphere is required to present a passport. Canadian citizens classified as Treaty Trader, Treaty Investor, or Fiancé(e) require a visa.

Entry of Non-Citizen Residents in Canada or Bermuda
Effective March 17, 2003, citizens of Ireland and nationals of British Commonwealth countries resident in Canada or Bermuda are required to present a valid non-immigrant visa for entry to the United States, unless they are a national of a country designated eligible to enter under the Visa Waiver Program. Information in obtaining a visa while in Canada is available on the Website of the U.S. Embassy in Ottawa, Canada.

Entry into the United States Under the Visa Waiver Program
The Visa Waiver Program (VWP) allows citizens of 27 countries to apply for entry to the United States without a nonimmigrant visa if they are seeking entry for 90 days or less as a visitor for business or pleasure. Applicants under the VWP must have a valid, unexpired passport. Countries designated under this program are: Andorra, Australia, Austria, Belgium, Brunei, Denmark, Finland, France, Germany, Iceland, Ireland, Italy, Japan, Liechtenstein, Luxembourg, Monaco, the Netherlands, New Zealand, Norway, Portugal, San Marino, Singapore, Slovenia, Spain, Sweden, Switzerland, and The United Kingdom.

Entry of Citizens of Mexico
In general, a citizen of Mexico must have a passport and nonimmigrant visa or Form DSP-150 (also known as a "Laser Visa"). Form DSP-150 is a biometric, machine readable, B1-B2 Visa/border crossing card that may be used to enter the United States from within the Western Hemisphere. If coming from outside the Western Hemisphere, a passport is required.