The development of a nuclear bomb that would be 24 times more powerful than the one dropped on Hiroshima, Japan, during World War II is “significantly ahead of schedule,” according to U.S. national security officials. 

“The National Nuclear Security Administration (NNSA) will complete the First Production Unit of the B61-13, a modern variant of the B61 nuclear gravity bomb, this fiscal year and significantly ahead of schedule,” an NNSA spokesperson told Fox News.

“One of seven warhead modernization programs to ensure the reliability and effectiveness of the U.S. nuclear stockpile, the B61-13 will provide additional options against certain harder and large-area military targets,” the spokesperson added. “NNSA accelerated delivery of the weapon by leveraging manufacturing processes from the related B61-12 program, whose final unit was completed in 2024, and implementing a range of technical innovations to optimize production.”

“Their creativity in system qualification put an aggressive set of plans in motion to meet stakeholder expectations,” Sandia National Laboratories said. 

The statement comes a day after President Donald Trump’s nominee for NNSA administration, former Rep. Brandon Williams, faced off with senators during his confirmation hearing. 

NNSA administrator nominee Brandon Williams testifies before the Senate Armed Services Committee on Tuesday, April 8, 2025.  (Handout)

Williams notably testified that he would not advise the resumption of nuclear detonation tests last conducted in the United States in 1992. He said the ultimate decision would be “above my paygrade” but that he would not recommend tests and instead preferred to rely on “scientific information,” such as computer modeling done at NNSA laboratories based on data gathered from nonnuclear detonation tests. 

His response came during a line of questioning by Sen. Jacky Rosen, D-Nev., who cited how “millions of people and acres of land were contaminated by radiation” during nuclear detonation testing conducted in her home state during the Cold War.