USA Assembles First B61-13 Nuclear Bomb

The United States has assembled the first B61-13 nuclear bomb, completing its development a year ahead of schedule.

The U.S. Department of Energy announced this on May 19, according to The War Zone.

The bomb is designed to strike heavily fortified underground military targets, including command centers.

The primary carrier of the B61-13 will be the next-generation American strategic bomber, the B-21 Raider.

The new bomb is based on its predecessor, the B61-12, but offers a higher maximum yield to enhance the flexibility and reliability of the U.S. nuclear deterrent.

Additionally, it is stated that the B61-13 features the same “modern safety, security, and accuracy capabilities” as the B61-12.

The media notes that all B61 versions are so-called “dial-a-yield” weapons, which can be set to detonate with varying levels of explosive power.

Although the exact figures are classified, the U.S. government has stated that the maximum yield of the B61-13 will match that of the earlier B61-7 version, which it is intended to replace in the American arsenal, with a maximum yield estimated between 340 and 360 kilotons.

In comparison, the declared maximum yield of the B61-12, deployed on U.S. Air Force aircraft, is only 50 kilotons.

The B61 family of gravity nuclear bombs has been in service with the U.S. since 1968. They are currently deployed at U.S. Air Force and NATO bases.

In January 2025, the United States announced the completion of the modernization of the B61-12 LPU bomb as part of its life extension program.

Overall, nuclear weapons will cost the U.S. $946 billion over the next decade, which is 25% more than the estimate from two years ago. This amount covers the arsenal’s operation, maintenance, and modernization from 2025 to 2034, with average annual spending of $95 billion.