Sen. Jim Inhofe told Newsweek that Beijing's recent test must serve as a "wake-up call" to U.S. leaders.
Milley's comments mark the first public acknowledgement of China's hypersonic weapons tests by the country's most senior uniformed official.
U.S. officials expressed surprise at the capabilities achieved by the Chinese military, according to a report by the Financial Times.
In a study published earlier this month, People's Liberation Army researchers discussed a model that could help the military land its future hypersonic UAVs.
The missile is claimed to be able to strike targets on land and sea from over 620 miles away and is capable of flying nine times the speed of sound.
The Air Force is investing in a project that could produce a new version of Air Force One capable of flying the president to any continent within a few hours.
A fleet of advanced hypersonic aircraft could be ferrying cargo and passengers to space by the middle of the century, according to a new report.
The Northern Fleet said it would conduct a new test with the Tsirkon anti-ship hypersonic cruise missile in the Barents Sea.
The Army hopes to field its first ground-launched hypersonic weapon by 2023, with more flight tests taking place this year.
The Missile Defense Agency this month awarded $277 million to L3Harris and Northrop Grumman as part of its Hypersonic and Ballistic Tracking Space Sensor project.
U.S. military officials have warned that America is lagging behind China and Russia in hypersonic weapons development.
"We all know perfectly well that so far there are no such weapons in the world, no one else, except us, except Russia," Russian President Vladimir Putin said.
The U.S. may seek to fight fire with fire when it comes to Russia's and China's hypersonic weapons.
Russia, China and the U.S. are racing to develop the best hypersonic technology for the military.
China revealed it's building the world's fastest wind tunnel only a month after offering a glimpse of its new hypersonic DZ-ZF missile glider.