North Korea said it successfully tested an advanced hydrogen bomb on Sunday, marking a dramatic escalation in the isolated state’s stand-off with the United States over its nuclear weapons programme.
Japanese and South Korean officials said an earthquake detected near the North’s test site was around 10 times more powerful than previous detonations, and concluded the North had conducted its sixth nuclear test.
It was the North’s first nuclear test since U.S. President Donald Trump took office, and marked a direct challenge to Trump, who hours earlier had talked by phone with Japanese Prime Minister Shinzo Abe about the “escalating” nuclear crisis in the region.
North Korea said in an announcement on state television that a hydrogen bomb test ordered by leader Kim Jong Un was a “perfect success” and a “meaningful” step in completing the country’s nuclear weapons programmes.
The bomb was designed to be mounted on its newly developed intercontinental ballistic missile (ICBM) the North said in the announcement, which came hours after the U.S. Geological Survey (USGS) reported a 6.3 magnitude quake.
A U.S. official who studies North Korea’s military and politics said it was too early to determine if a test supported the North’s claim that has succeeded in developing a thermonuclear weapon, “much less one that could be mounted on an ICBM and re-enter Earth’s atmosphere without burning up”.
The latest nuclear test comes amid heightened regional tension following Pyongyang’s two tests of intercontinental ballistic missiles (ICBM) in July that potentially could fly about 10,000 km (6,200 miles), putting many parts of the mainland United States within range.