China will insist the main principles of the Kyoto Protocol are retained in any new global climate change pact, even though others are seeking to abandon them, a high-ranking climate official on Saturday.

"China will carry out our negotiations on the basis of the Kyoto Protocol which we have adhered to all along," said Gao Guangsheng, director general at the department of climate change at the National Development and Reform Commission.

He told a conference that some countries were seeking to tear up the principle of "common but differentiated responsibilities" on which the Kyoto Protocol was founded.

According to the Kyoto principle, rich "Annex I" countries should take the initiative when it comes to reducing CO2 emissions, while poorer nations such as China and India would not be obliged to set their own mandatory targets until 2020.

Much of the legal infrastructure of the protocol is based on the principle, including the clean development mechanism, which allows developed countries to meet their CO2 targets by investing in clean projects in the developing world.

"But now there are some signatories trying to abandon the Kyoto Protocol, with some wanting to devise new laws," Gao said.

Gao did not name the United States, but the country's legislators are currently deliberating on a climate bill that would commit US industries to costly CO2 cuts, and many have expressed concern that if China doesn't follow suit, it will gain a competitive advantage in world trade.

With the first phase of the Kyoto Protocol set to expire in 2012, leaders will gather in the Danish capital of Copenhagen next month to thrash out the details of a new deal, but few expect anything binding to emerge.

Gao said China remained optimistic.

"Looking now at the progress of negotiations, you can say China is still full of hope about the meeting in Copenhagen," he said. "We are now putting our utmost effort into the success of the Copenhagen meeting."