Kim Jong-un's rockets are capable of reaching America but would not work when they got there, according to analysts.
The North Korean dictator carried out a test launch of his Hwasong-14 intercontinental ballistic missile in the north of the country on Friday.
US and South Korean experts have analysed Japanese footage capturing the rocket's re-entry vehicle shortly before it crashed into the sea.
They said the video suggests it failed to survive the extreme heat and pressure after re-entering the Earth's atmosphere following its launch.
But the apparent failure likely means the North will conduct more flight tests of the Hwasong-14 missile to ensure the warhead could survive the re-entry from space and hit its intended target, the analysts said.
North Korean dictator Kim Jong-un carried out a test launch of his Hwasong-14 intercontinental ballistic missile in the north of the country on Friday
Kim Jong-un's rockets are capable of reaching America but would not work when they got there, according to analysts
The Hwasong-14 ICBM, which was first tested on July 4, follows decades of effort by North Korea to obtain a nuclear deterrent against the United States.
Analysis of the flight data from Hwasong-14's second test has suggested that more of the U.S. mainland, including Los Angeles and Chicago, is now in range of Pyongyang's weapons.
However, whether North Korea can arm the missile with a nuclear warhead and protect it throughout the flight are different questions entirely.
After analyzing video from a rooftop camera operated by Japan's NHK television on the northern island of Hokkaido, U.S. missile expert Michael Elleman concluded that Hwasong-14's re-entry vehicle 'disintegrated' before it landed at sea.
In an article posted at the 38 North website, Elleman said the video showed the re-entry vehicle shedding small radiant objects at an altitude of 2.5 to 3 miles.
He said the re-entry vehicle dims and quickly disappears