As soon as the sun glints over miles of border fence dividing the United States and Mexico, the engines of cargo trucks packed with auto and computer parts roar to life along border bridges and bleary-eyed workers file into factories to assemble a multitude of products geared toward the U.

A line of Mexican National Guard and Army trucks are rumbling along the border separating Ciudad Juárez and El Paso, Texas, among the first of 10,000 officers Mexico has sent to its northern frontier following tariff threats by President Donald Trump.

Mexico's president shifted military troops to her country's northern border in a deal with Trump to target drugs, migrants.