TOPSHOT - A Central American migrant walks along the Rio Grande (also Rio Bravo), the river on US-Mexico border that divides the cities of Piedras Negras in Mexico's Coahuila State and Eagle Pass in Texas, US, on February 15, 2019. - President Donald Trump, repeating his claim that "walls work," announced Friday that he will declare a national emergency in order to build a barrier on the US-Mexico border without funding from Congress. (Photo by Julio Cesar AGUILAR / AFP)