President-elect Donald Trump will declare a national emergency at the U.S. southern border with Mexico on Monday and announce plans to send additional armed forces to help secure the border, an incoming Trump administration official said.

Trump signed a series of executive orders on border security following his inauguration Monday, fulfilling his political promise to crack down on immigration.

President Donald Trump rolled out a blueprint to beef up security at the southern border in a series of executive orders that began taking effect soon after his inauguration Monday, making good on his defining political promise to crack down on immigration and marking another wild swing in White House policy on the divisive issue.