North Korea threatened to use a nuclear weapon against Japan and turn the U.S. into “ashes and darkness” for passing fresh United Nations sanctions earlier this week — fiery rhetoric that is likely to exacerbate tensions in North Asia.

“Japan is no longer needed to exist near us,” the state-run Korean Central News Agency said Thursday, citing a statement by the Korea Asia-Pacific Peace Committee. “The four islands of the archipelago should be sunken into the sea by the nuclear bomb of Juche,” it said, a reference to the regime’s ideology of self-reliance.

Japanese Chief Cabinet Secretary Yoshihide Suga called the comments, which sent the Korean won lower, “extremely provocative.”

“If North Korea stays the course that it is on, it will increasingly become isolated from the world,” Suga said. “Through implementing the new United Nations Security Council resolution and related agreements, the international community as a whole needs to maximize pressure on North Korea so that it will change its policy.”

The latest U.N. sanctions follow North Korea’s sixth and most powerful nuclear test earlier this month. In late August, the regime launched a ballistic missile over northern Japan in what it said was “muscle-flexing” to protest annual military drills between the U.S. and South Korea. Leader Kim Jong Un called it a “meaningful prelude” to containing Guam. North Korea previously threatened to launch rockets over Japan into the Pacific and toward the U.S. territory.