Navy warship USS Gravely is on a mission to strengthen security at the U.S.-Mexico border, Pentagon officials said. Why it matters: The deployment of the guided-missile destroyer that last year was involved in shooting down Iran-backed Houthi rebels' ship attacks in the Middle East to a region the U.

The Trump administration is taking the unusual step of deploying a Navy warship off the waters of the U.S. as part of its broader crackdown on security and migration along the Mexico border.