In separate congressional hearings here Tuesday, senior Energy and Defense officials declined to pin down the date at which the National Nuclear Security Administration (NNSA) might start modifying an existing warhead to create the low-yield, submarine-launched weapon sought by the Trump administration.

The Pentagon has already requested 2019 funding to start work on upgrades for the Trident II D-5 missile that would carry the warhead, but the NNSA needs special permission from Congress to design, let alone create, the weapon. One way it could get that permission is for lawmakers to write it into this year’s National Defense Authorization Act: an annual military policy bill. Last year’s took until December to clear the legislature.

The head of the NNSA would not even speculate how long it might take to get that permission, either to lawmakers on the House Appropriations energy and water development committee, or to sister publication Weapons Complex Morning Briefing. Asked for a timeline for starting the work after a budget hearing here Tuesday, NNSA Administrator Lisa Gordon-Hagerty said only the agency is “working on it.”

During the hearing, the subcommittee’s ranking member, Rep. Marcy Kaptur (D-Ohio), did not bother to press Gordon-Hagerty for answers in an open forum, instead securing the NNSA chief’s promise to return at some point for a private briefing on “the NNSA’s plans regarding the NPR [Nuclear Posture Review] starting with the FY ’18 budget and beyond.”

The Trump administration, in the Nuclear Posture Review published Feb. 2, called for the NNSA to develop a low-yield, submarine-launched ballistic missile warhead to check similarly powerful Russian weapons. Later in February, then-acting NNSA Administrator Steven Erhart said this warhead would be a dialed-down W-76, which is now used on Trident II D-5 ballistic missiles carried aboard Ohio-class submarines. 

On the other side of Capitol Hill Tuesday, the commander of the the military’s nuclear forces was similarly vague about the NNSA’s timeline. The agency’s congressional authorization to start the work “will come in a fairly timely way,” Air Force Gen. John Hyten, commander of U.S. Strategic Command, said Tuesday during a hearing of the Senate Armed Services strategic forces subcommittee.

The Pentagon, in correspondence with the Hill obtained and published by the Washington-based Union of Concerned Scientists, said it requested more than $20 million in 2019 alone to start modifying the missiles that eventually will be tipped with the low-yield warhead.