North Korea's leader Kim Jong-un personally oversaw the successful launch of the hypersonic missile, the state media said, in a second such test in less than a week.
North Korea claims it has successfully test-fired a hypersonic missile, the second such launch by the nuclear-armed nation in less than a week.
The official Korea Central News Agency (KCNA) said on Wednesday that North Korea's leader Kim Jong-un personally oversaw the launch.
The missile carrying a "hypersonic gliding vehicle" hit "the set target in waters 1,000 km" away, KCNA said.
Photographs posted on the website of Rodong Sinmun, the official newspaper of the ruling Workers' Party, showed Kim Jong Un wearing a long black leather coat and using binoculars to watch the test from his mobile viewing platform.
"The superior manoeuverability of the hypersonic glide vehicle was more strikingly verified through the final test-fire," the KCNA report said.
Other images in Rodong Sinmun showed the missile blasting off from land at dawn in a blaze of fire and smoke, and Kim discussing charts with uniformed officials.
This is the third reported North Korean test of a hypersonic gliding missile.
The first, which took place four months ago, was followed by one last week, as the country looks to add the sophisticated weapon to its arsenal.
South Korea's military said the missile launched on Tuesday had reached hypersonic speeds and showed clear signs of "progress" from last week's test.
The missile flew 700 kilometres (435 miles) at an altitude of about 60 kilometres (37 miles) at Mach 10 speed, Seoul's Joint Chiefs of Staff said.
Hypersonic missiles travel at speeds of Mach 5 and higher and can manoeuvre mid-flight, making them harder to track and intercept.
Russia, the United States and China have reported successfully testing hypersonic glide vehicles.
Russia is generally seen as the world leader in the technology.
The Tuesday test came as the UN Security Council met in New York to discuss Pyongyang's weapons programmes.
At a key meeting of North Korea's ruling party last month, Kim vowed to continue building up the country's defence capabilities, without mentioning the United States.
Dialogue between Washington and Pyongyang remains stalled, and the country is under multiple sets of international sanctions over its nuclear and ballistic missile programmes.