We are working with our U.S. counterparts to ensure the UK replacement warhead remains compatible with the Trident missile. The UK Replacement Warhead will be designed, developed and manufactured in the UK. It will be housed in the Mk7 aeroshell, as will the U.S. W93 warhead, but the requirements, design and manufacture of the warheads are sovereign to each nation. This is consistent with our obligations under the Treaty on the Non-Proliferation of Nuclear Weapons.