North Korea says it has conducted a hydrogen bomb test in a surprise announcement that complicates already difficult efforts to curb the country’s push for a working nuclear arsenal.
The North said in a broadcast that the test was successful. A hydrogen bomb is generally more powerful than a nuclear bomb.
North Korea has long pushed for an arsenal of warheads that can be mounted on a missile capable of reaching mainland America’s shores. It is thought to have a handful of rudimentary nuclear bombs, but it is not yet thought to have succeeded.
South Korean officials earlier detected an “artificial earthquake” near North Korea’s main nuclear test site.
An H-bomb test will almost certainly lead to a push for new sanctions at the United Nations.
An announcer on state TV said North Korea had tested a ``miniaturised'' hydrogen bomb, elevating the country's ``nuclear might to the next level'' and providing it with a weapon to defend against the US and its other enemies.
The test was a “perfect success”, the announcer said.
In the first indication of a possible test, the US Geological Survey measured an earthquake with a magnitude of 5.1.
An official from the Korea Metrological Administration, South Korea’s weather agency, said the agency believed the earthquake was caused artificially based on an analysis of the seismic waves and because it originated 30 miles north of Kilju, the area where North Korea’s main nuclear test site is located. The country conducted all three previous atomic detonations there.
The test is a surprise, both in its purported type and its timing.
North Korea had not conducted an atomic explosion since early 2013, and leader Kim Jong Un did not mention the country’s nuclear weapons in his New Year’s speech.
Outside analysts speculated that he was worried about deteriorating ties with China, the North’s last major ally, which has shown signs of greater frustration at provocations and a possible willingness to allow strong UN sanctions.
The size of today’s quake is bigger than seismic activity reported in previous atomic bomb tests. Yonhap news agency reported that quake monitoring agencies detected magnitudes of seismic activity of 3.7 in 2006; 4.5 in 2009 and 4.9 in 2013.
After the North’s third atomic test, in February 2013, Pyongyang launched a campaign of rhetoric that included threats to launch a nuclear attack on the US and Seoul.
North Korea claimed in 2013 that it had scrapped the 1953 armistice that ended fighting in the Korean War. Pyongyang has also restarted a plutonium nuclear reactor shuttered after a 2007 nuclear deal that later fell apart.