HMS Prince of Wales, its newest carrier which was only formally commissioned into service in December 2019, broke down off England's south coast last week at the outset of its trans-Atlantic voyage.

In an embarrassing development, it had been due to participate in what the British navy had called a "landmark mission" involving stealth jet and drone exercises off the coast of North America and in the Caribbean.

Rear Admiral Steve Moorhouse said its sister ship, HMS Queen Elizabeth, would now stand in for the stricken vessel during some elements of the tour, which includes diplomatic events.

It is also expected to feature exercises with F-35B Lightning jets.

HMS Queen Elizabeth, which is the flagship of the UK's Carrier Strike Group that deployed to the Asia-Pacific region last year, will then sail to the Mediterranean and Baltic for planned exercises there this autumn.

Moorhouse revealed navy divers had inspected the 65,000-tonne pound3 billion Prince of Wales warship, which is sitting in a bay near its Portsmouth base, and found "significant damage to the shaft on the propeller".

"This is an extremely unusual fault and we continue to pursue all repair options," he said in a video posted on the Royal Navy's Twitter account, noting this would "probably" need to happen on a dry dock.

"We'll repair her, get her back on operations protecting the nation and our allies as soon as possible," he added.