North Korea says leader Kim Jong Un oversaw a successful flight test of a hypersonic missile he claimed would remarkably increase the country’s nuclear “war deterrent.”

The report by North Korean state media on Wednesday came a day after the militaries of the United States, South Korea and Japan said they detected North Korea firing a suspected ballistic missile into its eastern sea.

The Korean Central News Agency said Tuesday’s launch involved a hypersonic glide vehicle, which after its release from the rocket booster demonstrated “glide jump flight” and “corkscrew maneuvering” before hitting a sea target 1,000 kilometers (621 miles) away. Photos released by the agency showed a missile mounted with a pointed cone-shaped payload soaring into the sky while leaving a trail of orange flames and Kim watching from a small cabin with top officials.

The launch was North Korea’s second test of its purported hypersonic missile in a week, a type of weaponry it first tested in September, as Kim continues a defiant push to expand his nuclear weapons capabilities in the face of international sanctions, pandemic-related difficulties and deadlocked diplomacy with the United States.