Forbes:
In the eternal competition between offense and defense for military dominance, the offense is winning. Russia has been testing a hypersonic cruise missile with a speed above 6,000 miles per hour that can be used to deliver nuclear or conventional warheads against targets at sea or on land. The U.S. military at present has no defense against the weapon.
U.S. intelligence expects the missile, called Zircon, to be deployed on Russian warships in the near future. Meanwhile, Russia is testing a second hypersonic weapon, a glide vehicle boosted to speeds in excess of a mile per second by a ballistic missile, that is expected to carry a nuclear warhead over intercontinental distances. China has similar research under way, and has tested its own hypersonic system within the last year.