With US Secretary of State John Kerry set to arrive in Beijing, Foreign Ministry spokeswoman Hua Chunying said at a news briefing in the capital on Tuesday that US officials must "play a constructive role ... instead of pointing fingers at others".

Hua was responding to a question about recent remarks United States officials made on the Korean Peninsula nuclear issue.

"Many of these remarks were obviously irresponsible," she said.

Kerry, who was scheduled to arrive in Beijing on Tuesday after visiting Laos and Cambodia, was expected to press China to bear down on the Democratic People's Republic of Korea. Insiders have said he added China to his itinerary after the DPRK announced it successfully tested a hydrogen bomb on Jan 6.

Washington has long refused to talk with Pyongyang about a peace treaty, which is believed by some observers to be a major reason behind the nuclear test.

Fan Jishe, a US studies researcher at the Chinese Academy of Social Sciences, said: "The US has pressured the DPRK harshly for years, but that did not stop Pyongyang from pushing its nuclear program forward."

"Apparently, China does not believe increasing pressure would work. Actually, it could lead to regional turbulence, which would work against the interests of China, the Republic of Korea and also the US."

Xinhua contributed to this story.

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