The US Air Force just broke cover on its first new bomber in decades. See photos of the new B-21 Raider.

The Air Force unveiled the first new US stealth bomber in decades on Friday, following years of covert development.

The B-21 Raider is a sixth-generation aircraft intended to serve as the backbone of America's fleet amid increasingly rocky relations with China and Russia.

The sleek stealth bomber made by Northrop Grumman made its public debut at an Air Force facility in Palmdale, California.

The Friday event was the first time since 1988 that a new US bomber received a public unveiling.

The aircraft's first flight is projected for 2023, though the actual timing will depend on ground test outcomes, Northrop Grumman said.

Six B-21 test aircraft are currently being assembled at the company's Palmdale, California, site, according to the aerospace and defense manufacturer.

The B-21 Raider is optimized for high-end threat environments, Northrop Grumman said, with next-generation stealth technology, advanced networking capabilities, and an open systems architecture.

The aircraft is capable of delivering both conventional and nuclear payloads.

"The B-21 is the most advanced military aircraft ever built and is a product of pioneering innovation and technological excellence," Doug Young, sector vice president and general manager of Northrop Grumman Aeronautics Systems, said. "The Raider showcases the dedication and skills of the thousands of people working every day to deliver this aircraft."

But the new bomber also boasts several modern updates.

"The way it operates internally is extremely advanced compared to the B-2, because the technology has evolved so much in terms of the computing capability that we can now embed in the software of the B-21," Kathy Warden, chief executive of Northrop Grumman Corp, said, according to The Associated Press.

Among the likely updates are new propulsion technologies, more advanced stealth capabilities, and new controlling mechanisms for electronic emissions, defense analysts told The AP.

Earlier this year, the Air Force and Northrop Grumman successfully demonstrated the migration process.

The approach is an effort to drive affordability and readiness advantages, the company said.

The "Raider" name was submitted by airmen with the 337th Test and Evaluation Squadron of Eglin Air Force Base, Florida, according to CNN.

The moniker refers to the 1942 Doolittle Raid in which 80 volunteers retaliated against Japan with a bombing mission months after the Pearl Harbor attack.

"We wanted [to] ensure the aircraft had a strong name airmen could take pride in, especially those who will have the opportunity to fly and maintain the B-21," Lt. Col. Jaime Hernandez said in 2016. "We also wanted to take an element of our history into account, and the story of the Doolittle Raiders embodies just that."