The Royal Navy's flagship HMS Prince of Wales has departed on one of its biggest deployments yet.

The £3bn aircraft carrier set off from Portsmouth and will take part in exercises demonstrating the UK's ability to operate fast jets at sea, and carry out large scale military operations on the other side of the world.

Up to 24 of the latest F-35B stealth jets will join the carrier as it leads a multi-national fleet of warships to 40 countries across the Mediterranean, Middle East, south-east Asia, Japan and Australia.

The 65,000-tonne warship, which can hold up to 1,600 military personnel, will be deployed for eight months.

A Royal Navy spokesman confirmed the ensign on the flight deck of HMS Prince of Wales was at half-mast as a "mark of respect" for the late Pope.

Defence Secretary John Healey said: "I want to thank the thousands of our armed forces personnel involved in the delivery of this immensely complex operation, demonstrating the UK's world-leading capability to deploy a major military force around the world."

He added: "As one of only a handful of countries in the world able to lead a deployment of this scale, the Royal Navy is once again demonstrating its formidable capability while protecting British values and sending a powerful message of deterrence to any adversary."

In addition to the fighter jets are 16 Merlin and Wildcat helicopters, and a number of T-150 Malloy and Puma drones.

With fast moving world events and the ongoing conflicts in Ukraine and the Middle East, Commodore James Blackmore, commander of the strike group, said there was always a possibility that the programme could be changed.

"Agility allows me at any moment to undertake other operations if called upon," he explained.

The mission is called Operation Highmast.

Able Seaman James South, from Brighton, said he was both excited and apprehensive.

"It's the first very long deployment away from home for me so I'm curious to see what that brings," he said.

Able Seaman Molly Plant, from Cornwall, said: "I think it's the most people we've taken away on a deployment.

"It's a bit of a tight squeeze but everyone has a bed which is good."

Altogether, 2,500 personnel from the Royal Navy, almost 600 from the RAF, and about 900 from the British Army will take part in the exercises.

They should all be home in time for Christmas.