The real question should have been will the US even try and intercept a North Korean missile?:
The U.S. Defense Department says it could “likely” intercept a long-range North Korean missile before it reaches the American mainland.
Charles McQueary, director of operational tests and evaluation, told Bloomberg News that an the chance of interception is “likely” but not “highly likely.”
He also said Washington will likely launch multiple rockets at the incoming missile to raise the chance of interception.
South Korea and U.S. intelligence have reportedly detected signs at the Musudan-ri launch site in North Korea showing Pyongyang preparing to launch a Taepodong-2 long-range missile. [KBS Global]
If an AEGIS SM-3 or THAAD missiles were taking a shot at a Taepodong-2 I would be very confident of an intercept, however the 30 GBI’s currently deployed by the US military that have not undergone rigorous operational testing, who knows.
You can read more about the US’s missile defense options here.