he US Air Force has successfully tested a pair of Lockheed Martin hypersonic missiles, the Pentagon said, as concerns grow that Russia and China have had more success in developing their own weapons The AGM-183 ARRWs “reached hypersonic speeds” and “primary and secondary objectives were met” in the test off a B-52 bomber, Brig Gen Heath Collins, the programme manager, said in a statement on Wednesday. The test was conducted in Southern California a day earlier.

This was another important milestone for the Air Force's first air-launched hypersonic weapon," Brig Gen Collins said.

He said the Air Force completed its booster test series and can "move forward to all-up round testing" — which includes the booster and the warhead — later in the year.

The US hopes to declare an "early operational capability" for the weapon by sometime in the next fiscal year, a previous Air Force statement said.

Three failed attempts had derailed plans for the hypersonic missile to enter the production phase this year. Russia and China already have weapons that can move at fast speeds.

"This second successful test demonstrates ARRW's ability to reach and withstand operational hypersonic speeds, collect crucial data for use in further flight tests and validate safe separation from the aircraft," a Lockheed Martin statement said.

Hypersonic weapons travel at near 6,200 kilometres per hour, more than five times the speed of sound.

Separately, the Defence Advanced Research Projects Agency (Darpa) confirmed it had successfully performed the first test of its Operational Fires hypersonic weapon, at White Sands Missile Range in New Mexico.

Operational Fires is a ground-launched system that will "rapidly and precisely engage critical, time-sensitive targets while penetrating modern enemy air defences".

One of Lockheed Martin's concepts for the Darpa weapon is to use an existing Himars rocket launcher, similar to those sent to Ukraine.