In November 2022, the Air Force updated its safety rules for airlift of nuclear weapons to allow the C-17A Globemaster III aircraft to transport the new B61-12 nuclear bomb.

The update, accompanied by training and certification of the aircraft and crews, cleared the C-17A to transport the newest U.S. nuclear weapon to bases in the United States and Europe.

Interesting map showing locations of US Nuclear Bombs in Europe………………

https://fas.org/blogs/security/2023/01/c17-cleared-to-transport-b61-12/