U.S. President Donald Trump said on Tuesday he had signed a memorandum directing the attorney general to draw up regulations banning devices that turn firearms into machine guns, like the bump stock used in October's mass shooting in Las Vegas.

Trump told a ceremony at the White House for first responders that he expected the new regulations would be finalized "very soon."

(Reporting by Eric Walsh; Writing by Eric Beech; Editing by Mohammad Zargham) ((eric.beech@thomsonreuters.com; 202-898-8322; Reuters Messaging: eric.beech.reuters.com@reuters.net))