China will not improve on its pledges to control emissions, the country's top climate negotiator said on Thursday ahead of key UN climate change talks in Paris.

The world's largest polluter also chastised developed countries, with Xie Zhenhua -- a vice minister at China's top economic planner, the National Development and Reform Commission -- saying they have not done enough to combat rising temperatures.

According to the UN framework convention on climate change and the Kyoto Protocol, developed countries should cut emissions by significant amounts from 1990 levels by 2020.

"But developed countries' carbon emissions reduction strength has not yet reached [the required] level," Xie said at a press briefing in Beijing ahead of the Paris conference, implying they were not on course to live up to their promises.

His comments come before the UN Conference of Parties (COP21) summit, due in Paris from November 30 to December 11, where world leaders aim to forge an international deal to curb carbon emissions and stave off the worst effects of global warming.

China pledged last year to peak carbon output by "around 2030" -- suggesting at least another decade of growing emissions.

"At this point, our goal will not change," Xie said.

Campaigners portrayed Beijing as a villain of a failed previous summit in Copenhagen, which ended in bitter disappointment after Chinese officials resisted carbon reduction targets.

Beijing advocates what it calls "common but differentiated responsibilities", meaning developed countries should bear the brunt of climate regulations for their decades of uninhibited growth, fuelled mostly by coal.

"This is the key problem to be resolved for the success of the meeting and the reaching of an agreement," Xie said. "This is also a key issue and foundation for the building of political trust."

China's transformative economic boom has mainly been fuelled by coal, which provides most of its energy, and it plans to move 250 million more people from the countryside to cities in the next 10 years -- creating more buildings and car users.

The Asian giant is estimated to have released nine to ten billion tonnes of carbon dioxide in 2013, nearly twice as much as the US and around two and a half times the European Union.