When Dayana Castro heard that the U.S. asylum appointment she waited over a year for was canceled in an instant, she had no doubt: She was heading north any way she could. The 25-year-old migrant, her husband and their 4- and 7-year-old children had nothing left at home in Venezuela.

The US-Mexico border is effectively closed off to migrants seeking asylum in the United States within hours of President Donald Trump taking office, an extraordinary departure from previous protocols that has left many concerned migrants in limbo.

U.S. officials say the Pentagon will begin deploying as many as 1,500 active duty troops to help secure the southern border in the coming days.

The move enacts President Trump's executive orders issued shortly after he took office to intensify immigration enforcement.

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

A wildfire in the hills near the U.S.-Mexico border exploded early Friday morning over thousands of acres, prompting evacuation orders throughout the Otay Wilderness Area and triggering school closures as well as likely power shutoffs for tens of thousands of people.