China accused rich countries of undermining key elements of an international climate change agreement that nations hope to agree by the end of 2009, adding to a chorus of discord over the negotiations.
Su Wei, who led Beijing's delegation to climate treaty talks in Bangkok that ended on Friday, said splits over the framework for a new pact to fight global warming remained "quite large", just two months before negotiations culminate in Copenhagen.
China, as both the world's biggest developing country and world's biggest emitter of greenhouse gases from human activity, is at the heart of those disagreements.
Su told China's official Xinhua news agency that rich countries were seeking to abandon key principles of the Kyoto Protocol, the treaty that governs nations' efforts to address climate change up to the end of 2012.
Negotiators have been wrestling with whether to extend Kyoto into a second commitment period from 2013, amend the pact or create a new one, a step many developing nations resist.
Kyoto obliges rich countries to make quantified commitments to cut emissions of greenhouse gases that are stoking global warming, while developing countries do not have to assume quantified emissions targets.
Negotiators have been trying to find a formula that will bring the United States and developing nations into a framework that commits all nations to curb their emissions to prevent dangerous climate change.
Many developing nations want industrialised countries to cut emissions by at least 40 percent below 1990 levels by 2020. Current pledges are far below that.
But industrialised countries have been pressing for a new agreement that places clearer emissions obligations on emerging nations, especially China.
Reuters contributed to the report.