President Donald Trump issued a memorandum Friday giving the U.S. military jurisdiction over federal lands at the southern border.

President Trump justified the use of the military by saying the United States is "under attack from a variety of threats."

President Trump on Friday put the Pentagon in charge of a narrow strip of land along the U.S.-Mexico border, authorizing the military to detain immigrants suspected of crossing illegally. Why it matters: The latest directive builds on Trump's January executive order declaring illegal immigration a national emergency and ordering the military to secure the border.