The US Navy has announced a successful test of an electromagnetic cannon capable of firing a projectile 200 kilometres at five times the speed of sound.

"This demonstration moves us one day closer to getting this advanced capability to sea," said Rear Admiral Nevin Carr, chief of naval research.

Tested at the Navy's Dahlgren Surface Warfare Centre in Virginia, the futuristic weapon uses powerful jolts of electric current to propel a non-explosive slug along rails before launching it at supersonic velocities.

The latest test involved a 33-megajoule shot, the most powerful ever attempted and three times that of the previous test in January 2008.