The US Air Force (USAF) is expected to award the multi-billion dollar contract to build a new long-range strike bomber (LRS-B) within the next two months.

The USAF acquisition chief William LaPlante said that the source selection for the new bomber was going well, Reuters reported.

Competitors for the project include Northrop Grumman and a team of Boeing and Lockheed Martin.

The award of this contract will see the manufacturing of 80 to 100 new LRS-B aircraft for the Air Force at a unit cost of $550m.

"The award of the contract will see the manufacturing of 80 to 100 new LRS-B aircraft for the USAF at a unit cost of $550m."

The new bombers will replace the USAF’s aging B-52 Stratofortress and B-2 Spirit fleets.

LaPlante was quoted by the news agency as saying: "It’s only done when it’s really done.

"What I care about and everybody cares about, is that it’s done right."

The USAF issued a request for proposal for this LRS-B programme in July 2014.

LaPlante added: "It’s a much bigger issue than any one programme.

"All we can do is make sure that we don’t inadvertently, by something we control, all of a sudden push someone completely out of the market."

Northrop Grumman manufactures the B-2 bomber, while Boeing and Lockheed are currently developing the KC-46A tanker and F-35 Lightning II joint strike fighter (JSF) aircraft for the USAF under separate programmes.

Under agreement between Boeing and Lockheed Martin, the former will act as the prime contractor for the project, while latter will serve as the primary teammate.