KCNA said it "precisely hit" a set target 700km (434 miles) away.
This is the second reported test of a hypersonic missile, which can avoid detection for longer than ballistic missiles.
The test comes as its leader Kim Jong-un had earlier vowed to bolster Pyongyang's defences.
Mr Kim said in a New Year's speech that Pyongyang would continue to strengthen its defence capabilities due to an increasingly unstable military environment on the Korean peninsula.
North Korea tested a variety of missiles last year amid stalled talks with the South and US.
Pyongyang joins a small number of countries, including the United States and China, in attempting to develop hypersonic missiles.
The latest launch was first detected by the Japanese coast guard early on Wednesday, before being confirmed by defence authorities in Seoul.
The Democratic People's Republic of Korea (DPRK) has confirmed that it conducted a hypersonic missile test launch into the sea on Wednesday, according to the official Korean Central News Agency (KCNA).
ReplyDeleteThe missile successfully traveled 435 miles (700 km) to hit its target, making a 75 mile (120 km) lateral maneuver along the way, the KCNA reported Thursday morning.
"In the test launch, the academy reconfirmed the flight control and stability of the missile in the active-flight stage and assessed the performance of the new lateral movement technique applied to the detached hypersonic gliding warhead," the report said.
The agency did not provide further details about the location of the test.
The Joint Chiefs of Staff (JCS) of the Republic of Korea (ROK) said in a statement on Wednesday morning that the DPRK had fired an unidentified projectile toward the East Sea from the DPRK's inland area at about 8:10 a.m. local time.
China on Wednesday urged all relevant parties to cherish the "hard-won" peace and stability on the Korean Peninsula.