While there, the defense secretary will likely announce hundreds of more troops who will join the military's expanded role in enforcing immigration.

In recent remarks to the press, President Donald Trump restated his intention to impose 25% tariffs on U.S. imports from Mexico and Canada as early as Feb. 1. His reasoning: "vast" illegal immigration and "massive" amounts of fentanyl coming to the U.

A border wall near Imperial Beach in California was reinforced as Trump intensified his crackdown on immigration crime. Footage shows U.S. Marines from the 1st Combat Engineering Battalion, 1st Marine Division,