WASHINGTON, Oct 21 ― US President Joe Biden said yesterday he is concerned about Chinese hypersonic missiles, days after a media report that Beijing had tested a nuclear-capable hypersonic glide weapon.

Asked by reporters as he was boarding Air Force One for a trip to Pennsylvania whether he was concerned about Chinese hypersonic missiles, Biden said, "Yes.”

Hypersonic weapons travel in the upper atmosphere at speeds of more than five times the speed of sound, or about 6,200 kph (3,853 mph).

The Financial Times said at the weekend that China had tested a weapon in August that flew through space and circled the globe before cruising down toward a target that it missed. China's foreign ministry denied the report.

The test took place as the United States and its global rivals quicken their pace to build hypersonic weapons - the next generation of arms that rob adversaries of reaction time and traditional defeat mechanisms.

"Hypersonic weapons are strategic game-changers with the dangerous potential to fundamentally undermine strategic stability as we know it,” Senator Angus King of Maine said on Monday, adding that "the US cannot lag in this development or allow for blind spots as we monitor the progress of our competitors.”

The White House has raised concerns about Chinese hypersonic missile technology through "diplomatic channels,” spokesperson Jen Psaki told reporters yesterday.

In September, the Pentagon's Defence Advanced Research Projects Agency successfully tested an air-breathing hypersonic weapon capable of speeds faster than five times the speed of sound. It was the first successful test of the class of weapon since 2013.

Companies such as Lockheed Martin and Raytheon Technologies are working to develop the US.s hypersonic weapon capability.

Hypersonic weapons are potential "nightmare weapons,” King said. "The implications of these weapons under development by China or Russia could be catastrophic.” ― Reuters