WASHINGTON — A U.S. general says the nation currently has no defense against new hypersonic weapons being developed by the Chinese and Russians.

Gen. John Hyten, the head of U.S. Strategic Command, said the weapons still need several years of development, but that without missile defense upgrades, the U.S. will be unable to detect them when they are operational, according to CNN.

Hypersonic weapons travel at speeds over Mach 5, or 3,806 mph. Hypersonic missiles are launched into space, but then reenter the atmosphere and fly at high speeds on a flight path similar to an aircraft.
The lower altitude trajectory make them more difficult for U.S. missile defense satellites and radars to pick them up.

Hyten said the U.S. would need to first upgrade its sensor capabilities as well as develop more effective interceptor missiles with more lethal warheads.