The United States has produced the first B61-13 bomb — the latest version of the primary thermonuclear gravity weapon in the Air Force arsenal.
The introduction of the first B61-13 in May 2025 marks a significant achievement because it was completed almost a year ahead of schedule and less than two years after the program’s inception, according to a June 2025 news release from the National Nuclear Security Administration (NNSA). The U.S. has prioritized efforts to revitalize its defense industrial base to quicken weapons development and manufacturing.
“The remarkable speed of the B61-13’s production is a testament to the ingenuity of our scientists and engineers, and the urgency we face to fortify deterrence in a volatile new age,” U.S. Secretary of Energy Chris Wright said during a May 2025 ceremony at the Amarillo, Texas, facility where U.S. nuclear weapons are assembled, according to the NNSA release.
Wright said modernization of the country’s nuclear stockpile is essential.
“It was my honor today to stamp the first completed unit at the Pantex Plant … where all the efforts of NNSA’s labs, plants and sites culminated in this amazing milestone,” Wright said. “This achievement signals American strength to our adversaries and Allies alike.” The stamp signifies the bomb’s quality and readiness for deployment.
The higher-yield B61-13 was developed to give the U.S. more capability against hardened underground targets. The bomb will be reserved for use by the B-2 Spirit and forthcoming B-21 Raider stealth bombers, according to a May 2025 story by military news website The War Zone. The U.S. Air Force’s stealth bombers are a valuable capability for U.S. Strategic Command, whose mission includes strategic deterrence and nuclear operations. The B61-13 will not increase the number of weapons in the U.S. nuclear stockpile, according to a June 2025 report in Sandia Labs News, the in-house publication of Sandia National Laboratories. The number of B61-12 units produced was reduced by the planned production goal for the new bombs.
The “B61 family” of weapons is the longest-serving in the U.S. nuclear stockpile, according to the NNSA. The B61 was first deployed in the 1960s and more than a dozen variants have been developed, with some still in service. Much of the B61-13’s design is based on the B61-12, which ended production in 2024.
“We definitely would not have been able to go this fast had we not been leveraging a significant portion of the design and especially the qualification data from the B61-12 to ensure the weapon is safe and secure,” Arthur Gariety, weapon systems lead for the B61-13, told Sandia Lab News.
Sandia National Laboratories, which is part of the NNSA, served as lead systems integrator and design agency for the nonnuclear B61-13 components.
The data gleaned from the decades of B-61 development allowed for the new bomb’s greatly accelerated production. This was accomplished, in part, by “streamlining or in some cases combining … the rigorous reviews conducted at each step of a weapon design process,” according to the NNSA news release.
“I’m confident many of these practices can be applied to future weapon modernization efforts, with promising implications for their delivery timelines,” David Hoagland, the acting deputy administrator for defense programs, said in the NNSA release.