The Pentagon has deployed a Navy destroyer on an unusual mission to bolster security at the southern U.S. border, defense officials said, dispatching a warship involved last year in combat in the Middle East to waters typically patrolled by the U.

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.