America, France, and the UK. They are able to be utilized by other NATO members if those three decide it is necessary.

>A number of NATO member countries contribute a dual-capable aircraft (DCA) capability to the Alliance. These aircraft are central to NATO’s nuclear deterrence mission and are available for nuclear roles at various levels of readiness. In their nuclear role, the aircraft are equipped to carry nuclear bombs in a conflict and personnel are trained accordingly.

[July 2022] https://www.nato.int/cps/en/natohq/topics_50068.htm

>Currently, seven Allies voluntarily participate in the NATO nuclear mission by contributing DCA. As implied by its name, DCA serve two roles. The first is to provide conventional air power capabilities, such as air policing and combat support, on a day-to-day basis. The second is to operationally deploy nuclear weapons in a conflict, following a political decision by the NPG. DCA are also a visible and valuable instrument for strategic communications. In a crisis or conflict, DCA could be used to send deterrence signals about operational readiness or to demonstrate resolve.

[PDF February 2022] https://www.nato.int/nato_static_fl2014/assets/pdf/2022/2/pdf/220204-factsheet-nuclear-sharing-arrange.pdf