UK Carrier Strike Group reaches Japan, operates F-35Bs from JS Kaga

The UK Carrier Strike Group (UKCSG) led by the aircraft carrier HMS Prince of Wales arrived at Yokosuka Naval Base in Japan on 12 August 2025, having concluded an international naval exercise in the Philippine Sea.

The nine-day exercise saw the UKCSG integrate with a Japan Maritime Self-Defence Force (JMSDF) battle group led by the helicopter carrier JS Kaga, the US Navy’s Carrier Strike Group Five led by the aircraft carrier USS George Washington and the US Marine Corps (USMC) Amphibious Ready Group centred on the amphibious assault ship USS America.

The UKCSG escorts that participated in the exercise comprised the UK Type 45 destroyer HMS Dauntless, UK Type 23 frigate HMS Richmond, Norwegian Fridtjof Nansen-class frigate HNoMS Roald Amundsen, Australian Hobart-class destroyer HMAS Brisbane and Spanish Álvaro de Bazán-class frigate ESPS Méndez Núñez, supported by the UK replenishment tanker RFA Tidespring. In total, 11 warships and 23 aircraft from six nations took part.

The exercises in the Philippine Sea included anti-submarine warfare serials, co-ordinated air defence drills and replenishment operations. They also included the first instance of a British jet landing on a Japanese warship when a pair of 617 Squadron F-35B Lightning Joint Strike Fighters from HMS Prince of Wales landed on and then took off from JS Kaga on 8 August. This will have been of particular interest to the JMSDF since, although Japan has only received four F-35Bs so far of 42 it has on order, JS Kaga and sister ship JS Izumo are undergoing multi-phase refits to convert them from helicopter destroyers to light aircraft carriers each able to host 14 F-35Bs.

The cross-decking activities to build interoperability also saw allied helicopters, including the Merlin Mk4s of 845 Naval Air Squadron, flying to and from Japanese ships, the USMC’s VMFA-242 squadron temporarily detaching two F-35Bs to HMS Prince of Wales and USMC MV-22 Osprey tiltrotors from USS America practising landings on the UK carrier.

The UKCSG has had to deal with a few F-35 issues during its deployment. Before HMS Prince of Wales arrived in Japan three UK F-35Bs were detached for Operation ‘Hightower’: an exercise with the air forces of Japan and South Korea. When one of these suffered an in-flight malfunction on 10 August it had to make an emergency diversion to Kagoshima Airport in southwest Japan. Prior to this a UKCSG F-35B was stranded at Thiruvananthapuram airport in the southern Indian state of Kerala from 14 June until 22 July after developing a fault.

On the 80^th anniversary of VJ Day – 15 August 2025 – the ship’s company of HMS Prince of Wales will hold a short service of remembrance on board the aircraft carrier’s flight deck, led by a Royal Navy chaplain and including a minute’s silence.

During its time in Japan HMS Prince of Wales will undergo mid-deployment maintenance and host a programme of defence and industry events. From late August to early September 2025 the carrier will visit Tokyo for a planned series of events.

The UKCSG as a whole will then conduct further exercises and engagements in the Asia-Pacific region before beginning its return transit.