SEOUL – North Korea said Wednesday it conducted a hydrogen bomb test, a significant advance in its pursuit of a nuclear arsenal.
A television anchor read a typically propaganda-heavy statement on state TV that said North Korea had tested a “miniaturized” hydrogen bomb, elevating the country’s “nuclear might to the next level.”
Crowds dressed in thick winter coats gathered outside a large video screen near a Pyongyang train station to cheer and take video and photos on their mobile phones of the televised announcement. Some people raised their hands and applauded. Many smiled and cheered.
The state-run Korean Central News Agency said the test was conducted “for self-defense.”
“The Korean Peninsula and its vicinity are turning into the world’s biggest hot spot, where a nuclear war may break out” amid a constant presence of nuclear-armed U.S. forces, it said.
It added, Pyongyang now possesses an “H-bomb of justice.”
Seismological sensors recorded a magnitude-5.1 tremor on Wednesday morning at or near North Korea’s test site.
If confirmed by outside experts, the test will likely lead to a strong push for tougher sanctions at the United Nations. It will also worsen already abysmal relations between Pyongyang and its neighbors.
In Tokyo on Wednesday, Prime Minister Shinzo Abe condemned the North’s action, calling it a “serious threat” to Japan and a “grave challenge’ ” to nuclear nonproliferation efforts.
“I strongly condemn this,” Abe told reporters.
“The nuclear test . . . is a serious threat to the safety of our nation and we absolutely cannot tolerate this,” he said.
South Korea said it will consult with allies and regional powers to get North Korea to face consequences such as additional U.N. sanctions.
“We strongly condemn” the test, Presidential security official Cho Tae-yong said.
The nuclear test is also a slap in the face to the North’s sole major ally, China, and extinguish any chance of a resumption of six-country nuclear talks that Beijing has been pushing for.
China’s state Xinhua News Agency said Wednesday a test of a nuclear bomb by North Korea runs counter to the goal of denuclearization. It said any practice that disrupts stability in northeast Asia is “undesirable and unwise.”
North Korean nuclear tests worry Washington and others because each new blast is seen as pushing North Korea’s scientists and engineers closer to their goal of an arsenal of nuclear-tipped missiles that can reach the United States.
While a hydrogen bomb is more powerful than an atomic bomb, it is also much harder to make. In a hydrogen bomb, radiation from a nuclear fission explosion sets off a fusion reaction responsible for a powerful blast and radioactivity.
Some analysts questioned whether Wednesday’s test was indeed of a hydrogen device.
“North Korea has made claims about its nuclear and missile programs in the past that simply have not held up to investigation,” said Melissa Hanham, a Senior Research Associate at the California-based James Martin Center for Nonproliferation Studies.
Yang Uk, a senior research fellow at the Korea Defense and Security Forum, added: “Given the scale it is hard to believe this is a real hydrogen bomb. They could have tested some middle-stage kind (of device) between an A-bomb and H-bomb, but unless they come up with any clear evidence, it is difficult to trust their claim.”
North Korea is thought to have a handful of rudimentary nuclear bombs and has spent decades trying to perfect a multistage, long-range missile to eventually carry smaller versions of those bombs. After several failures, it put its first satellite into space with a long-range rocket launched in December 2012.
Experts say that ballistic missiles and rockets in satellite launches share similar bodies, engines and other technology. The U.N. called the 2012 launch a banned test of ballistic missile technology.
Some analysts say the North is unlikely to have achieved the technology needed to manufacture a miniaturized warhead that could fit on a long-range missile capable of hitting the U.S. But there is a growing debate on just how far the North has advanced in its secretive nuclear and missile programs.
North Korea has 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 Kim 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 U.N. sanctions.
The size of the tremor in Wednesday’s incident is bigger than seismic activity reported in previous atomic bomb tests. Yonhap said quake monitoring agencies detected magnitudes of seismic activity of 3.7 in 2006; 4.5 in 2009 and 4.9 in 2013. Wednesday’s capped the lot, at 5.1 as measured by the U.S. Geological Survey.
After the North’s third atomic test, in February 2013, Pyongyang launched a campaign of bellicose rhetoric that included threats to launch a nuclear attack on the United States and Seoul. North Korea declared 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.
In its statement Wednesday, KCNA said its nuclear arsenal is non-negotiable, for now.
“There can neither be suspended nuclear development nor nuclear dismantlement on the part of the DPRK unless the U.S. has rolled back its vicious hostile policy toward the former,” it said.
Since the elevation of the young Kim in 2011, North Korea has ramped up angry rhetoric against the leaders of allies Washington and Seoul and the U.S.-South Korean annual military drills it considers invasion preparation.