Canada, Mexico and the United States face a growing threat posed by the spread of avian influenza and the potential emergence of a human influenza pandemic. The highly pathogenic (HPAI) H5N1 avian influenza virus, which re-emerged in Asia in late 2003, has already spread to Europe, the Middle East and Africa. Although the virus has not yet reached North America, Canada, Mexico and the United States must be prepared for the day when it—or some other highly contagious virus—does. At the March 2006 Security and Prosperity Partnership of North America (SPP) summit in Cancun, the leaders of Canada, Mexico and the United States committed to developing a comprehensive, coordinated and science- based North American approach to prepare for and manage avian and pandemic influenza. The North American Plan for Avian and Pandemic Influenza outlines how Canada, Mexico and the United States intend to work together to combat an outbreak of avian influenza or an influenza pandemic in North America. The Plan complements national emergency management plans and builds upon the core principles of the International Partnership on Avian and Pandemic Influenza, the standards and guidelines of the World Organization for Animal Health (OIE), the World Health Organization (WHO)—including the revised International Health Regulations, as well as the rules and provisions of the World Trade Organization (WTO) and the North American Free Trade Agreement.