The new type of intermediate-range ballistic missile launched by North Korea on Sunday is a "game changer", according to analysts, because it uses a solid fuel engine that makes the weapon more stable and reduces the time required to fuel a missile before launch.

The Pukguksong-2 is also road-mobile on tractor-erector-launcher units, analysts point out, all of which means that the weapon is more difficult to detect and neutralise before it is launched.

"The liquid fuel engines that North Korea uses in all its medium- and long-range missiles are dangerous because the fuel is so corrosive and volatile", said Lance Gatling, a defence analyst and president of Tokyo-based Nexial Research Inc.