TOPSHOT - A Central American migrant moving towards the United States in hopes of a better life, remains at the U.S.-Mexico border fence in Playas de Tijuana, Mexico, on November 15, 2018. - US Defence Secretary Jim Mattis said Tuesday he will visit the US-Mexico border, where thousands of active-duty soldiers have been deployed to help border police prepare for the arrival of a "caravan" of migrants. (Photo by ALFREDO ESTRELLA / AFP)