U.S. Vice President Joseph Biden met Monday with Mexican President Felipe Calderon in Mexico City, the first stop on a two-day trip to Mexico and Honduras. Biden was scheduled to meet later with the three main candidates for the Mexican presidency ahead of July 1 elections. The United States and Mexico are close trading partners as part of the North American Free Trade Agreement (NAFTA), which also includes Canada. In Honduras, Biden will hold talks with President Porfirio Lobo and meet with Central American leaders ahead of the Summit of the Americas to be held in Colombia next month.