President Donald Trump’s promised crackdown on illegal immigration has begun to take shape in San Diego County, as federal agents launched targeted operations to arrest undocumented immigrants and a wave of military troops got to work reinforcing U.

An additional 1,500 troops have arrived at the U.S.-Mexico border after President Donald Trump declared a national emergency in one of his first official acts.

Officials said the fire, which had spread to more than 500 acres by Thursday night, was miles away from threatening any homes or buildings.

The Mexican government has criticized President Donald Trump’s unilateral immigration actions, and the landing would have required Mexico’s assistance.

U.S. officials say active duty military troops are arriving in El Paso, Texas, and in San Diego on Thursday evening.

CBS 8 spoke with Cal Fire San Diego on how crews battle fires that happen on the Mexico side of the U.S.-Mexico border.

"It's unprecedented," said Ciudad Juarez municipal official Enrique Licon as workers unloaded long metal bracings from tractor trailers parked in the large empty lot yards from the Rio Grande in order to build a tent city for deportees from the United States.

The search and advertising giant said it would change its Google Maps names to Mount McKinley and Gulf of America once they're officially changed by federal officials.

It was chaos week in the Mountain West as the conference’s top four NCAA Tournament contenders — Boise State, New Mexico, San Diego State and No. 22 Utah State

A fire spreading through the wilderness of San Diego County near the U.S.-Mexico border exploded to more than 500 acres within several hours on Thursday night. But the blaze, known as the Border 2 fire, was miles from any structures or homes, and firefighters said they were making progress controlling it.

Trump ended use of a border app to allow migrants to enter the country on two-year permits with eligibility to work, canceling tens of thousands of appointments into early February for people stranded in Mexico. Nearly 1 million people entered the U.S. at land crossings with Mexico by using the CBP One app.