The UK Royal Navy's nuclear attack submarine HMS Astute has test-fired Tomahawk land-attack missiles in the Gulf of Mexico.
During the testing, conducted as a part of the first test run of the system, the submarine fired a series of missiles at up to 550mph.
Each 5.5m-long Tomahawk missile weighed 1,300kg and had a range of 1,000 miles.
The 97m-long submarine can move at a submerged speed of 54km/h without having to refuel.
It can carry 38 weapons including a combination of Spearfish heavy torpedoes and Tomahawk Block IV cruise missiles.
HMS Astute will continue with the trials in the US before returning to the UK next year to begin training for its first operational deployment.