North Korea on Monday claimed to have added another potent weapon that poses a grave threat to Japan to its already formidable arsenal, with Pyongyang confirming that it had “successfully” tested a solid-fueled intermediate range ballistic (IRBM) missile a day earlier.

The missile, which the South Korean military said had flown around 1,000 kilometers, was “loaded with a hypersonic maneuverable controlled warhead,” according to the North’s official Korean Central News Agency.

“The test-fire was aimed at verifying the gliding and maneuvering characteristics of intermediate-range hypersonic maneuverable controlled warhead and the reliability of newly developed multi-stage high-thrust solid-fuel engines,” KCNA said in a brief report Monday.