U.S. President Joe Biden said on Wednesday 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.
The White House has raised concerns about Chinese hypersonic missile technology through "diplomatic channels," spokesperson Jen Psaki told reporters on Wednesday.
In September, the Pentagon's Defense 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.