China on Wednesday criticized the lack of action by developed nations in fulfilling their commitments on carbon emissions reduction and financial support to developing nations in coping with climate change.

"You will find a huge gap if you make a comparison between their pledges and the actions they have so far taken," Yu Qingtai, China's special representative in the UN climate talks, said at a press conference during the UN Climate Change Conference in Copenhagen.

Developing nations are asking for at least 300 billion U.S. dollars in financial support to help them deal with the impacts of climate change. Developed nations' financial commitments have fallen far short of that goal, and no money has actually been provided.

Financial support for developing nations is not "charity work" of the rich nations, but their "legal obligations" under international conventions, Yu said.

On emission cuts, the United States' 4-percent pledge by 2020 compared with 1990 levels and the European Union's 20-percent goal are also criticized by developing nations as being not enough.

Rich nations have pledged to reduce their emissions to 1990 levels by 2000, but none of them has fulfilled that commitment, Yu said.

They should reflect on whether they have the "true political will" to make good on their pledge, he said. "In this regard, what they need to do is some soul-searching."

"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 developed nations, Yu said.

In response to a U.S. call for incorporating China's commitment into an international treaty, Yu said the United States and other rich nations were trying to "blur the fundamental differences in the responsibilities developed and developing nations take respectively."