NAFTA: Canada's & Mexico's Viewpoints When the Canada/U.S. free trade agreement came into effect, the Mexican's were very impressed by the provision and opportunities that opened for both sides. Mexico then approached the U.S., seeking to form a similar agreement with them. This brought forth a new issue in Canada, should they let Mexico and the U.S. form an agreement without them? Or should they participate, thus transforming their deal with the U.S. into a trilateral agreement including Mexico. On June 12, 1991, the trade ministers of Canada, the United States and Mexico met in Toronto to open negotia