Tokyo - Japan, South Korea and the United States on Saturday ratcheted up pressure on China to support the "strongest possible" punishment against North Korea, following Pyongyang's nuclear test earlier this month.
Japan's Vice Foreign Minister Akitaka Saiki, US Deputy Secretary of State Antony Blinken and their South Korean counterpart Lim Sung-Nam held a one-day meeting at a Tokyo guesthouse, where they called on Beijing to support a strong UN Security Council resolution targeting Pyongyang.
"We strongly hope that China, as its neighbour and the most influential country on North Korea, will fully co-operate with the international community to adopt a strong resolution," Saiki told a joint news conference.
Saiki said the three countries are aiming to help adopt a UN resolution with the "strongest possible contents at the earliest timing".
China, a permanent member of the United Nations Security Council, is North Korea's economic benefactor, but traditional ties have become strained as Beijing's patience has worn thin with Pyongyang's behaviour and unwillingness to rein in its nuclear weapons ambitions.
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.
"It's our expectation along with our colleagues... that China will demonstrate a real leadership at the Security Council with us in assuring that there are significant consequences for North Korea's actions," Blinken said.
"The bottom-line is that the failure to take significant measures now almost guarantees that North Korea will continue to repeat this exercise of testing nuclear weapons," he added.
The call came after South Korean President Park Geun-Hye on Wednesday also urged the international community, and in particular China, to back harsh sanctions targeting Pyongyang over the nuclear test.
North Korea says its latest nuclear test was of a miniaturised hydrogen bomb - a claim largely dismissed by experts who argue the yield was far too low for a full-fledged thermonuclear device.
But whatever the nature of the device, it was North Korea's fourth nuclear test since 2006, and further evidence of Pyongyang's intention to continue developing its nuclear weapons capability in the face of international censure.