This segment originally aired Nov. 10, 2016, on VICE News Tonight on HBO.President-elect Donald Trump has promised to build a wall on the United States’ southern border, but undocumented immigration from Mexico has actually fallen dramatically over the past decade.Today, it’s Central American migrants who make up a growing share of those crossing into America illegally. Before they get to America’s border, they have to cross Mexico’s southern border, more than a thousand miles away.“Hunger and violence are much stronger than any inhibitor, than any closed border, any pursuit,” Friar Thomas Gonzalez told VICE News correspondent Daniel Hernandez in Tenosique, Mexico. “As long as there aren’t the conditions to live with dignity in Central America, people will be here, in all of Mexico, trying to reach the United States.”In 2014, under pressure from Washington, Mexico stepped up patrols, checkpoints and immigration sweeps along its southern border in order to crack down on illegal immigration from Central America. But the country’s informal economy now includes many cabs and vans used for human smuggling.“I’d like to work and help my family,” migrant Gervin Valle said in La Técnica, Guatemala. “We’re going to achieve the American dream.”Read next: The US already has a border wall and it’s basically useless