The US Air Force will determine how many Northrop Grumman B-21 bombers are needed for the fleet after the first aircraft is fielded in the 2020s, according to the service’s deputy chief of staff for strategic deterrence and nuclear integration.

The number of strategic bombers the air force will purchase is an ongoing discussion and the decision will be made after the B-21 "gets on the ramp", Lt Gen Jack Weinstein said following an Air Force Association event outside Washington, DC, on Thursday. Previously, the service called on bomber contractor Northrop to develop and build at least 100 nuclear-capable B-21s to replace the Rockwell B-1 and Boeing B-52.

“We’re not making that decision right now because we don’t need to,” he says. “So we’ll determine what that needs to look like. We’re doing a lot of analysis right now to determine how many bombers we need for the force based on all the warplanes that will help educate and allow us to make a decision on the breadth of B-21s.”

The entire fleet of B-21s will be both conventional and nuclear-capable, and the Air Force has built a timeline for when the aircraft will be nuclear-certificated, Weinstein said.

Some in Congress have attacked the USAF for shrouding the B-21’s costs in secrecy and more recently, critics have argued the B-21 and the proposed Long-Range Standoff (LRSO) weapon’s penetrating capabilities would prove redundant. The air force plans to purchase 1,000 LRSOs and employ them on the B-52, Northrop B-2 and B-21.

Weinstein countered that the USAF needs the B-21, whether in its nuclear or conventional form, because the B-2 will not be able to penetrate in the future based on advanced anti-access area denial environments.