Just days after North Korea test fired an intercontinental ballistic missile (ICBM) that experts say is capable of reaching major U.S. cities like Los Angeles, Denver, and Chicago, new video footage suggests that a key part of the missile broke into pieces upon re-entering the earth’s atmosphere. The evidence—taken by the Japanese public broadcaster NHK—was first identified by Michael Elleman, a missile expert at the International Institute for Strategic Studies in London, who blogged about the issue on 38 North, a research site affiliated with Johns Hopkins University.

According to Elleman, the missile’s re-entry vehicle (RV) shed “small radiant objects” before dimming as it returned to the earth’s atmosphere on Friday, suggesting that it disintegrated prematurely. “Had the RV survived the rigors of re-entry,” he writes, “it would have continued to glow until disappearing behind the mountains.” Here’s more from his analysis:

A reasonable conclusion based on the video evidence is that the Hwasong-14’s re-entry vehicle did not survive during its second test. If this assessment accurately reflects reality, North Korea’s engineers have yet to master re-entry technologies and more work remains before [North Korean leader] Kim Jong Un has an ICBM capable of striking the American mainland.

This finding is indeed significant, given the international response to North Korea’s latest ICBM test. On Saturday, President Trump criticized China for doing “nothing” to alleviate North Korea’s continued missile testing after receiving “hundreds of billions of dollars a year” from trade with the U.S. “We will no longer allow this to continue,” Trump warned, though his strategy remains unclear. As my colleague Krishnadev Calamur pointed out earlier today, imposing diplomatic pressure—including hefty sanctions—on North Korea has done little to curb the nation’s missile program, which Kim Jong Un seems intent on pursuing at all costs.