Speaking to reporters at the Pentagon on Friday, Mattis declined to say whether the missile North Korea launched earlier this week had a controlled re-entry into the atmosphere.
Pyongyang claimed on Monday that the missile reached an altitude of about 2,000 kilometers (1,200 miles) and was capable of carrying “a large, heavy nuclear warhead.”
Gaining the ability to control a missile's re-entry into Earth's atmosphere from space would be a big step forward for the North Korean missile program.
North Korea has made no secret of its desire to develop missiles capable of targeting some of its neighbors and intercontinental ballistic missiles capable of delivering a nuclear warhead to the U.S. mainland.
