China, the world’s biggest greenhouse gas emitter, wants rich nations to vow bigger cuts to emissions as part of a new international deal on fighting global warming, Beijing’s top climate negotiator said on Tuesday.

The negotiator, Xie Zhenhua, said he expects “arduous” wrangling about that and other issues facing governments seeking to settle on the key parts of a comprehensive climate change pact at talks in Durban, South Africa, in late 2011.

Above all, Xie said in a policy-setting essay in China’s official People’s Daily, Beijing will not budge from demanding a second lease of life for the Kyoto Protocol, the greenhouse gas emissions pact which Japan, Russia, Canada and other critics have said does too little to curb the fast-growing emissions of China and other big developing countries.