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 vessel is commonly used in overseas missions. The Coast Guard typically takes a lead role in security missions at sea close to the United States.

Donald Trump has deployed the US navy to the southern border amid a rise in small boat crossings by illegal migrants.

The USS Gravely is participating as part of the Defense Department's response to Trump's executive orders on the border, officials said.