According to South Korea's military, North Korea has fired a suspected submarine-launched ballistic missile into waters off the coast of Japan.
In January, Pyongyang unveiled the missile, calling it "the world's most powerful weapon."
It comes just weeks after South Korea unveiled a comparable weapon.
North Korea has conducted a series of missile tests in recent weeks, including weaponry that it claimed were hypersonic and long-range. Some of these tests are in violation of stringent international sanctions. The UN specifically prohibits North Korea from testing ballistic missiles as well as nuclear weapons.
Ballistic missiles are considered more dangerous than cruise missiles by the UN because they can carry more powerful payloads, have a longer range, and can fly quicker.
South Korea's Joint Chiefs of Staff announced on Tuesday that one missile had been launched from the port of Sinpo, which is located in the east of North Korea and is where Pyongyang's submarines are usually based. It landed in the East Sea, often known as the Sea of Japan. They mentioned that they suspected it was a submarine-launched ballistic missile.
According to South Korean media, this missile was believed to have travelled approximately 450km (280 miles) at a maximum height of 60km.
Fumio Kishida, Japan's PM, stated two ballistic missiles had been launched, labelling the launches "extremely regretful."