NORTH KOREA SAYS SUCCESSFULLY CONDUCTED FIRST -H BOMB TEST

By James Pearson and Tony Munroe
SEOUL (Reuters)

- North Korea said it successfully tested a
miniaturized hydrogen nuclear device on Wednesday,
claiming a significant advance in its strike capability and
setting off alarm bells in Japan and South Korea.
The test, the fourth time the isolated state has exploded a
nuclear device, was ordered by young leader Kim Jong Un
and successfully conducted at 10:00 a.m. local time (2030
ET), North Korea's official KCNA news agency said.
"Let the world look up to the strong, self-reliant nuclear-
armed state," Kim wrote in what North Korean state TV
displayed as a handwritten note.
The nuclear test drew condemnation abroad, with China,
the North's chief ally, expressing "resolute opposition" and
saying it would lodge a protest with Pyongyang.
While a fourth nuclear test had been long expected, the
claim that it was a hydrogen device, much more powerful
than an atomic bomb, came as a surprise, as did the timing.
It ensures that North Korea will be a key topic during the
U.S. presidential campaign.
North Korea has long coveted diplomatic recognition from
Washington but sees its nuclear deterrent as crucial to
ensuring the survival of its third-generation dictatorship.
"With Iran being off the table, the North Koreans have
placed themselves at the top of the foreign policy agenda
as far as nation-states who present a threat to the U.S.",
said Michael Madden, an expert on the country's secretive
leadership.
South Korean intelligence officials and several analysts
however questioned whether Wednesday's explosion was
indeed a full-fledged test of a hydrogen device.
The device had a yield of about 6 kilotons, according to the
office of a South Korean lawmaker on the parliamentary
intelligence committee - roughly the same size as the
North's last test, which was equivalent to 6-7 kilotons of
TNT.
"Given the scale, it is hard to believe this is a real hydrogen
bomb," said Yang Uk, a senior research fellow at the Korea
Defence and Security Forum.
"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."
Joe Cirincione, a nuclear expert who is president of
Ploughshares Fund, a global security organization, said
North Korea may have mixed a hydrogen isotope in a
normal atomic fission bomb.
"Because it is, in fact, hydrogen, they could claim it is a
hydrogen bomb," he said. "But it is not a true fusion bomb
capable of the massive multi-megaton yields these bombs
produce".
The United States Geological Survey reported a 5.1
magnitude quake that South Korea said was 49 km (30
miles) from the Punggye-ri site where the North has
conducted nuclear tests in the past.
North Korea's last test of an atomic device, in 2013, also
registered at 5.1 on the USGS scale.
The test nevertheless may mark an advance of North
Korea's nuclear technology. The claim of miniaturizing,
which would allow the device to be adapted as a weapon
and placed on a missile, would also pose a new threat to the
United States and its regional allies, Japan and South
Korea.
The North's previous miniaturization claims have not been
independently verified. Many experts also doubt whether
the North possesses missile technology capable of reliably
delivering a warhead to the continental United States.
UN MEETING
The White House said it could not confirm North Korea's
claims of miniaturization and a hydrogen bomb test, but
added the United States would respond appropriately to
provocations and defend its allies.
Prime Minister Shinzo Abe said Japan would make a firm
response to North Korea's challenge against nuclear non-
proliferation.
"North Korea’s nuclear test is a serious threat to our
nation’s security and we absolutely cannot tolerate it," Abe
told reporters. "We strongly denounce it."
South Korea said it would take all possible measures,
including possible United Nations sanctions, to ensure
Pyongyang paid the price after its fourth nuclear test.
"The government must now work closely with the
international community to ensure that North Korea pays
the commensurate price for the latest nuclear test,"
President Park Geun-hye said in a statement. "We must
respond decisively through measures such as strong
international sanctions."
North Korea has been under U.N. Security Council sanctions
since it first tested an atomic device in 2006 and could
face additional measures. The Security Council will meet
later on Wednesday to discuss what steps it could take,
diplomats said.
While the Kim regime boasts of its military might to project
strength globally, it also plays up the need to defend itself
from external threats as a way to maintain control
domestically.
The North's state news agency said it will not give up its
nuclear program as long as the United States maintained
what it called "its stance of aggression".
The nuclear test came two days ahead of what is believed
to be Kim's birthday.
The North called the device the "H-bomb of justice" and
said: "The U.S. is a gang of cruel robbers which has worked
hard to bring even a nuclear disaster to the DPRK," using
the official acronym for North Korea.
However, the agency said Pyongyang will act as a
responsible nuclear state and vowed not to use its nuclear
weapons unless its sovereignty was infringed. It said it will
not transfer its nuclear capabilities to other parties.