US officials identify type of North Korean missile fired over Japan U.S. officials identified it as a KN-17 intermediate-range missile.

 -- The missile fired by North Korea over Japan in a major act of aggression has been identified as a KN-17 intermediate-range missile, according to a U.S. Department of Defense official.

The South Korean military said the missile, known in North Korea as a Hwasong-12, flew 1,667 miles horizontally and about 310 miles at its top altitude after being launched early Tuesday local time. The Japanese government said the missile landed in the Pacific Ocean 733 miles east of Cape Erimo, the southernmost point on Hokkaido Island.

The single-stage, liquid-fueled KN-17 was fired from a mobile launcher north of North Korea's capital, Pyongyang, according to the U.S. official. The missile broke up toward the end of its flight, the official said, and the Pentagon is still conducting an assessment as to why.

But the official added that the U.S. military does not believe Tuesday's launch was a test of a re-entry vehicle. While North Korea has demonstrated it can now reach targets on the U.S. mainland, U.S. officials say it has still not mastered the technology needed for a nuclear warhead to survive re-entry through the earth's atmosphere.

No other missile movements have been detected in North Korea that could indicate another launch is in the works, said the official.

U.S. intelligence labels North Korean missiles with the letters KN followed by a number.

On Friday, North Korea fired three short-range missiles that landed in the Sea of Japan, two of them traveling about 150 miles. U.S. officials identified those missiles as short range Scud missiles.

North Korea has used the KN-17 to great effect since overcoming a string of launch failures with the rocket earlier this year.

U.S. officials said that two-stage intercontinental ballistic missiles that North Korea fired in July were based on the KN-17. One official described the ICBMs as "KN-17 hybrids," since the smaller second-stage components were placed on top of what was essentially a KN-17 body.