China's envoy to the world climate change talks in Copenhagen has criticised rich countries for failing to fulfil commitments to curb carbon emissions and provide aid to developing nations.
The comments from the envoy, Yu Qingtai, came after another official said a Chinese government minister had been blocked several times from entering the venue for the marathon UN talks in the Danish capital.
"You will find a huge gap if you make a comparison between their pledges and the actions they have so far taken," Yu told a press conference on Wednesday in Copenhagen, the state Xinhua news agency reported.
The Chinese envoy said rich nations needed to do some "soul-searching" to determine whether they had the "political will" to make good on earlier promises to reduce emissions from 1990 levels, as well as new initiatives.
He also said the developed world had not fulfilled a pledge to provide financial support to developing nations to help them cope with the effects of climate change.
Developing nations are asking for at least 300 billion dollars in assistance, which Yu said was not "charity work" but the "legal obligation" of developed nations under current international conventions.
"On the issue of tackling climate change, we have no lack of legal documents, but a lack of sincerity for taking action" on the part of the developed world, Yu told reporters, according to Xinhua.
The 12-day climate talks in Copenhagen are tasked with forging a deal to curb greenhouse gases, and help poor countries cope with the consequences of global warming already under way.
China, the world's top carbon emitter, has proposed that by 2020, it will curb emissions per unit of gross domestic product by between 40 and 45 percent compared to 2005 levels -- in essence, a massive energy-efficiency drive.
That means China would slow growth in its fast-rising emissions, but not reduce them. Beijing has argued that as a developing nation, it should be exempt from cutting them outright.
Yu said in Copenhagen that developed nations including the United States were trying to "blur the fundamental differences in the responsibilities developed and developing nations take respectively".