On Tuesday authorities in South Korea and Japan detected the suspected launch, which drew condemnation by authorities around the world and prompted an expression of concern from the U.N. secretary-general.
The second test of a "hypersonic missile" in less than a week underscored Kim's New Year's vow to bolster the military with cutting-edge technology at a time when talks with South Korea and the United States have stalled.
After watching the test, Kim urged military scientists to "further accelerate the efforts to steadily build up the country's strategic military muscle both in quality and quantity and further modernize the army," KCNA news agency reported.
It was the first time since March 2020 that Kim had officially attended a missile test.
U.N. Security Council resolutions ban all North Korean ballistic missile and nuclear tests and have imposed sanctions over the programs.
Talks aimed at persuading North Korea to surrender or limit its arsenal of nuclear weapons and missiles have stalled, with Pyongyang saying it is open to diplomacy but only if the United States and its allies stop "hostile policies" such as sanctions or military drills.
U.S. Under Secretary of State for Political Affairs Victoria Nuland called the launches dangerous and destabilising.
