The U.S. Navy has banned the release of news about its accelerated effort to develop and build unmanned or robot surface warships for its future fleet.

Media outlets requesting updates to the Navy's Sea Hunter unmanned surface vessel were told that all information related to this robot warship built to hunt down and destroy submarines of the People's Liberation Army Navy (PLAN) and the Russian Navy is now classified.

Sea Hunter's status has now been given a classified designation, said Bob Freeman, a spokesman for the Office of Naval Research (ONR) when asked for the status of this robot weapon.

Apparently also on the "keep it secret list" is information about the new and larger robot surface warships the Navy previously said it will develop. The most recent news about progress in this regard was a statement that a wide range of unmanned vessels is on the drawing boards.

 "Those capabilities will be delivered over the next couple years and start to get into our procurements in '18 and '19 and really start hitting the fleet," said Rear Adm. John Neagley, Littoral Combat Ship Program Executive Officer.

To underscore the huge importance of unmanned warships to the Navy, Adm. Neagley's office has since been renamed "PEO Unmanned and Small Combatants." PEO stands for Program Executive Office.

Sea Hunter is a small trimaran autonomous unmanned surface vehicle (USV) launched in 2016. The world's first robot warship, Sea Hunter was developed by the U.S. Defense Advanced Research Projects Agency (DARPA).

This weapon was developed part of DARPA's Anti-Submarine Warfare Continuous Trail Unmanned Vessel (ACTUV) program. She was christened at Portland, Oregon in April 2016.

Sea Hunter is classed as a Medium Displacement Unmanned Surface Vehicle (MDUSV). She weighs 140 tons and is capable of patrolling 18,500 km (10,000 nautical miles) of the ocean without a human crew.

She was transitioned from DARPA to the Office of Naval Research in February 2018. The first prototype of Sea Hunter was tested outside of Pearl Harbor, Hawaii in November 2018.

Sea Hunter should enter service with the United States Third Fleet sometime this year. In the 2020s, Sea Hunter will be used for anti-submarine and counter-mine duties and will be armed with either torpedoes or anti-submarine missiles.

The Navy will use its experience with Sea Hunter to scale-up this 40 meter-long trimaran to a warship the size of a frigate -- or even larger.

Rear Adm. Ron Boxall, Director, Surface Warfare (OPNAV N96), said his command is looking closely at what might be needed for a large unmanned surface warship, much like Sea Hunter.