TIJUANA, MEXICO - JANUARY 27: A Mexican flag monument is displayed on January 27, 2017 in Tijuana, Mexico. U.S. President Donald Trump announced a proposal to impose a 20 percent tax on all imported goods from Mexico to pay for the border wall between the United States and Mexico. Mexican President Enrique Pena Nieto canceled a planned meeting with President Trump over who would pay for Trump's campaign promise to build a border wall. (Photo by Justin Sullivan/Getty Images)