The US Navy’s newest Freedom-class littoral combat ship, USS Milwaukee (LCS 5), has experienced a loss of propulsion at sea.

The $360m LCS was enroute to Little Creek, Virginia, US, when it broke down approximately 40nm off the coast of Norfolk, Virginia.

USNS Grapple (T-ARS 53) towed the ship to Joint Expeditionary Base (JEB) Little Creek-Fort Story.

"The ship’s complete loss of propulsion was deeply alarming given this ship was commissioned just 20 days ago."

The ship is set to undergo full diagnostics and repair, according to the US Navy.

Initial investigation actions by the ship’s crew found the cause to be very fine metallic debris in the port and starboard combining gear filter system.

Similar debris was also discovered in the metallic debris contamination of the filter.

Senate Armed Services Committee Chairman John McCain was quoted by CNN as saying that the ship’s "complete loss of propulsion… was deeply alarming, particularly given this ship was commissioned just 20 days ago."

USS Milwaukee was commissioned on 21 November and was to be homeported in San Diego with sister ships.

McCain further added that the navy will "conduct a thorough investigation into the root causes of this failure, hold individuals accountable as appropriate, and keep the Senate Armed Services Committee informed."

Capable of reconfiguring for surface warfare, anti-submarine warfare and mine countermeasures, the 388ft-long USS Milwaukee is powered by four axial-flow waterjet engines to improve performance.