State media trumpeted the "miraculous" launch of what it claimed was a new Hwasong-17 intercontinental ballistic missile on March 24, publishing dramatic photos and videos of leader Kim personally overseeing the test.

But analysts identified discrepancies in Pyongyang's account, and South Korean and US intelligence agencies have concluded that North Korea actually fired a Hwasong-15 -- a less-advanced ICBM which it had already tested in 2017.

Why would North Korea do this? Analysts say it urgently needed a domestic propaganda victory ahead of a key anniversary, after the real launch of the Hwasong-17 a week before ended in failure with the missile exploding above the capital Pyongyang.