Just when it looks like North Korean leader Kim Jong Un may restart his ballistic missile testing program, U.S. President Donald Trump has proposed trimming the missile defense budget, as one set of deterrents is delayed by two years.

The U.S. Missile Defense Agency (MDA) — charged with developing, testing and fielding a ballistic missile defense system — will delay the expansion of the Ground-based Midcourse Defense (GMD) system by two years because of a delay in the redesign of the Raytheon Co.-made "kill vehicle" the system uses.

A "kill vehicle" pops off the top of the defending missile above the Earth's atmosphere and seeks out and destroys the attacking missile's warhead.