The United States and its two main military allies in Asia, South Korea and Japan, pledged a combined push Thursday to secure a comprehensive, hard-hitting international response to North Korea's latest nuclear test.

The leaders of the three countries, who have long sought to project a united front against the North Korean nuclear threat, spoke by phone a day after Pyongyang's shock announcement that it had tested its first hydrogen bomb.

Their consultations followed a meeting of the 15-member UN Security Council in New York which, with backing from China, Pyongyang's sole major ally, strongly condemned the test and said it would begin work on a new UN draft resolution that would contain "further significant measures."
UN diplomats confirmed that talks were under way on strengthening several sets of sanctions that have been imposed on secretive North Korea since it first tested an atomic device in 2006.

In South Korea, the mood was uncompromising, with President Park Geun-Hye calling for a strong international response to what she called a "grave provocation."

Park spoke with US President Barack Obama on Thursday morning, with both leaders insisting that the test merited the "most powerful and comprehensive sanctions," her presidential office said in a statement.

-- Paying the price --

"The two leaders agreed that the North should pay the appropriate price... and vowed to closely cooperate to get a strong resolution adopted at the UN Security Council," it added.

Japanese Prime Minister Shinzo Abe also spoke with Obama and agreed that they should spearhead the effort to impose harsher penalties on Pyongyang.
"We will take firm and resolute steps, including considering measures unique to our nation," Abe said, hinting at unilateral moves.

The censure and sanctions threats had a familiar ring, given similar outrage that greeted the North's previous tests in 2006, 2009 and 2013, and some voices stressed the need to find a strategy that combined coercion with negotiation.

"A priority must be to find ways to both further pressure North Korea to limit its nuclear weapons capabilities and engage it diplomatically," said David Albright, president of the Washington-based Institute for Science and International Security.

In announcing that it had successfully tested a hydrogen bomb, North Korea said it had "joined the rank of advanced nuclear states" like Russia, France and the United States that also boast thermonuclear devices.

The order to test was personally signed by leader Kim Jong-Un, with a handwritten message to begin 2016 with the "thrilling sound of the first hydrogen bomb explosion."

-- Scepticism --
Acquisition of a working H-bomb -- with a destructive power that dwarfs the bombs it has tested in the past -- would represent a massive leap forward in the North's nuclear weapons capability.

But experts said the explosive yield from Wednesday's test -- initially estimated at between six and nine kilotons -- was far too small.

"The initial analysis that has been conducted... is not consistent with North Korea's claim of a successful hydrogen bomb test," White House spokesman Josh Earnest said.

"There is nothing that has occurred in the last 24 hours that has caused the United States government to change our assessment of North Korea's technical and military capabilities."
Japan said three planes it sent up Wednesday to try and collect traces of radioactive material that might help clarify the nature of the test, had returned empty-handed.

At the UN, US Ambassador Samantha Power called for a "tough, comprehensive and credible package of new sanctions" to make clear to Pyongyang that there are "real consequences" to its actions.

Japanese Ambassador Motohide Yoshikawa said he will be pushing for "a series of measures under chapter 7" of the UN charter, which provides for enforceable sanctions.

But there was no real clarity on what form the sanctions might take, or when the package would be drawn up.

Currently, there are a total of 20 entities and 12 individuals on the UN sanctions blacklist, which provides for a global travel ban and an assets freeze.

-- Spotlight on China --

All eyes at the UN will now be on China, a veto-wielding council member, to see just how far it will go in tightening the sanctions grip on its recalcitrant neighbour.

While Beijing has restrained US-led allies from stronger action against Pyongyang in the past, it has shown increasing frustration with its refusal to suspend testing.

But China's leverage over Pyongyang is mitigated, analysts say, by its overriding fear of a North Korean collapse and the prospect of a reunified, US-allied Korea directly on its border.

There was no immediate response from North Korea to the UN sanctions threat, but its KCNA official news agency was unrepentant.

"The more frantic the hostile forces get in their moves to isolate and stifle the DPRK (North Korea), the stronger its nuclear deterrent will grow," it said in a commentary.
Source: AFP