Washington, Seoul and Tokyo have been lukewarm towards Beijing's proposal on Tuesday for emergency talks between the six regional powers, worried they could be perceived as rewarding Pyongyang for its deadly attack on a South Korean island two weeks ago.

The powers want China to bring its ally North Korea to heel, pressure Beijing has repeatedly resisted.

"The responsibility of maintaining peace and stability in Northeast Asia should be shouldered by all parties in the region," China's foreign ministry spokeswoman Jiang Yu told a regular news conference.

"All parties are stakeholders. We call on the parties to positively respond to our proposals to resolve the conflict through dialogue and negotiation."

On Monday, US Secretary of State Hillary Clinton held talks with her Japanese and South Korean counterparts, saying all three shared grave concerns over "provocative attacks from North Korea”.

China was not invited to Monday's trilateral meeting in Washington which put the onus on Beijing to take action.

Meanwhile, on Tuesday, China took a more belligerent tone calling allegations that it was shielding Pyongyang's nuclear programme an "irresponsible accusation".

China dilemma
Analysts say that China is reluctant to lean too hard on the North in the midst of a leadership transition, for fear of a collapse that could spark an exodus of refugees and allow US troops in South Korea right up to the Chinese border.

"China is in a deepening dilemma: how to struggle with the balance between maintaining ties with Pyongyang and maintaining cooperation with Washington," said Zhu Feng, professor of international relations at Peking University.

"Maybe Beijing may be more motivated now to wake up to a new reality."

On Monday, the International Criminal Court's prosecutor said it had opened a preliminary investigation into whether North Korean forces committed war crimes in South Korea, ramping up pressure on the isolated government in Pyongyang.