Unless things have changed, ALL nuclear weapons in the U.K. arsenal are owned by the U.S.A. and are provided on lease.
The UK nuclear warheads are manufactured at AWE Aldermaston and UK owned. The Trident D5 missiles, however, are leased from the USA and drawn from a common maintenance pool with the USN.
The UK warheads do not contain permissive active links are under the sole control of the crew.
The production of the warheads does rely on components purchased from the USA and depend on US systems such as GPS, but then so does the JSF.......
https://publications.parliament.uk/p...86/986we13.htm