Russia has tested their hypersonic missile Avangard. This missile is capable of reaching speeds of up to Mach 27 making it a missile without any defense.
Because of the American anti-missile systems, Russia has been developing weapon systems that could overcome them. And during Christmas during tested one such weapon.
In the past years, USA has built several new anti-missile systems against Ground Based Midcourse Defense rockets found in Alaska and California. Plus they have the AEGIS system found on warships and in Romania and many other systems. While experts generally agree that in case of a massive assault from a country with enough firepower these systems would not be enough Russia is still concerned that if the USA ever attacked them these systems could prevent them from retaliating.
New weapons should change that and one of them is the new Avangard missile. Based of available information Avangard uses a scramjet engine allowing it to reach speeds of up to Mach 27. Against such a fast missile all current anti-missile systems would be useless. Avangard is capable of using conventional explosives or a nuclear warhead with up to 2 megatons of TNT in yield.