Thousands of British troops have been deployed as part of a large-scale NATO mission amid growing fears over the threat of a wider conflict involving Russia. The UK’s flagship aircraft carrier HMS Prince of Wales left Portsmouth earlier this week, leading the Royal Navy’s most important mission of the year. Known as Operation Highmast, the eight-month deployment will see the UK Carrier Strike Group join forces with a dozen allies to carry out drills across the Mediterranean, Middle East and Indo-Pacific.

The task group will start with around 2,500 personnel - including 2,100 British troops - but that figure will rise to more than 4,500 for key exercises. The mission comes just after senior Russian official Sergei Shoigu warned of a possible World War 3 scenario, claiming any move by Western forces to deploy troops in Ukraine could spark a direct clash with NATO. Shoigu, one of Vladimir Putin’s closest allies, also said Moscow is ready to use nuclear weapons if it feels its sovereignty is threatened.

The Royal Navy says the deployment is designed to “demonstrate credible deterrence” and reinforce the UK’s support for NATO and international security.

“This will reaffirm that the UK is secure at home and strong abroad,” said Commodore James Blackmore, who is leading the operation from aboard HMS Prince of Wales.

The carrier group will be joined by destroyer HMS Dauntless, frigate HMS Richmond, Canadian and Norwegian warships, and a Royal Fleet Auxiliary tanker.

They’ll be backed by F-35B fighter jets, helicopters, drones and around 750 air wing personnel.

Drills will include aerial defence exercises off France, operations with an Italian-led carrier group, and later missions in Japan and Australia.

The Defence Secretary John Healey said: “As one of only a few nations capable of leading a deployment of this scale, the Royal Navy is once again demonstrating that UK defence is strong, modern, and ready to meet the threats of today and tomorrow.”

The mission comes against a backdrop of increasing global instability.

Shoigu recently claimed that Europe is preparing for war with Russia by 2030 and warned that “a direct clash between NATO and Russia” could lead to a nuclear conflict.

He added: “Russia reserves the right to use nuclear arms in the event of aggression, including with the use of conventional weapons.”

As the UK joins its allies in strengthening NATO’s position, Captain Will Blackett, commanding officer of HMS Prince of Wales, said: “This ship is a fantastic machine - but it only works thanks to the magic brought by the 1,600 people on board.”

The deployment will run until December.