Cartwright outlined the potential threat posed by North Korean missiles in testimony before the Senate Armed Services Committee. North Korea’s Taepodong 2 missile is designed to reach the West Coast of the U.S., but test launches to date have been partial failures.

Analysts believe the Taepodong 2 is inaccurate and so far has failed to reach a third stage, a critical leap to be able to hit the United States.

Cartwright said that in three to five years, the government in Pyongyang might be able to overcome its technical problems.

But he said that time frame did not include development of a warhead.