The upper echelons of the Department of Energy’s nuclear weapons apparatus shed no light Wednesday on exactly when they will begin producing the low-yield W76-2 submarine-launched ballistic missile warhead — a modified version of the W76-1 warhead whose just-completed modernization drew a who’s who of agency leadership to Amarillo, Texas.

Lisa Gordon-Hagerty, administrator of the National Nuclear Security Administration (NNSA), said only the semiautonomous DoE branch “is on track to meet DoD requirements for this national security mission.”

Gordon-Hagerty and her boss, Secretary of Energy Rick Perry, discussed the W76-1 milestone at the Pantex Plant, which assembles all U.S. nuclear weapons. In a social media first for the agency, the NNSA streamed the event live on Facebook. The proceedings marked December’s culmination of a $4 billion, two-decade, agency-wide endeavor that refurbished some 1,500 warheads with modern parts designed to keep the weapons reliable for another 30 years.

Perry, who dumped his prepared remarks in favor of a freewheeling “thank you” to agency personnel, did not mention W76-2 during the live stream.

Also on hand for the event were the directors of the Lawrence Livermore, Los Alamos, and Sandia national laboratories: respectively, William Goldstein, Thomas Mason, and Stephen Younger. Each received awards for their site’s contribution to the decades-long life-extension program, which produced its first war-ready W76-1 in 2008. Los Alamos and Sandia, both headquartered in New Mexico, were the lead labs on the W76-1 life extension.

The Trump administration ordered the low-yield W76-2 in the Nuclear Posture Review released in February 2018. The warhead, the White House says, is needed to stop Russia from using similarly powerful weapon to win a war it starts, but cannot finish, with conventional weapons.

Last year, the GOP-led Congress appropriated $65 million for the NNSA to start building it in fiscal 2019, which began Oct. 1. Sen. Dianne Feinstein (D-Calif.) has said the weapon will need another $60 million in 2020. The agency plans to build the W76-2 using the personnel and equipment that in December produced the final war-ready W76-1.

Rep. Adam Smith (D-Wash.), chair of the House Armed Services Committee after Democrats took control of the House in the November midterm elections, has vowed to cancel the W76-2.