Amid talk of Donald Trump's plans to build a border wall between the United States and Mexico, Mexico itself has an invisible wall along its southern border with Central America as migrants head north.

A Financial Times story details Mexico's role in stopping people from getting into its country from Guatemala. A reported 175,000 Central Americans were deported from Mexico in 2015 (a 68 percent jump from 2014), and so far in 2016 that number is approaching 100,000.

The Times claims the U.S. is sending Mexico $75 million in the form of equipment and training to help shore up its southern border. Ultimately, some of the Central American migrants wind up at America's southern doorstep. Stopping them from entering Mexico is the first line of defense.

A U.S. Border Patrol agent said earlier this year the U.S. should borrow a page out of Mexico's security playbook and strengthen its border defenses and deport more illegals when they arrive.

Trump said he has a plan for Mexico to pay for a border wall, which Mexican President Enrique Peña Nieto said will not happen.

The Financial Times reports than an estimated 400,000 Central Americans illegally enter Mexico every year.