DURBAN, South Africa - China's top climate negotiator said he is upbeat about the possibility of progress as talks enter a second week, despite differences among countries on issues such as the extension of the Kyoto Protocol and the creation of a Green Climate Fund.

"These are two major talking points for negotiators here in Durban," said Xie Zhenhua, deputy minister of the National Development and Reform Commission. "However, this week we need to settle on how nations can take concrete action before 2020."

The Kyoto Protocol is the only international climate treaty that binds industrialized countries to targets on reducing greenhouse gas emissions. The first commitment period expires next year.

United Nations climate chief Christiana Figueres said she has seen positive signs, as countries "begin to understand where a common ground could be found".

"The discussion is no longer whether we will have a second commitment period, but rather how governments would like to conform to that," she said.

A negotiation draft with more than 130 pages was readied at the weekend for arriving heads of state and ministers to narrow down options over the coming week.

Developing nations have insisted that the extension of the Kyoto Protocol is a cornerstone for the whole climate regime.

However, Japan, Canada and Russia have said they will not renew emissions-reduction pledges under the protocol, while the European Union wants to start negotiations for a new climate deal that binds all countries.

The United States never ratified the Kyoto Protocol and said it will not do so unless China and India also agree to a new treaty.

China showed flexibility during the first week of negotiations by saying it is open to talks about the EU's new condition, as well as offering the possibility to limit carbon emissions after 2020, a move welcomed by analysts and observers.

"China will continue to play a constructive role and adopt an open attitude in talking with other countries, and we're confident progress can be made," Xie told journalists on Sunday before the formal launch of China Pavilion, a series of events and workshops to showcase the country's efforts to fight climate change.

Feng Shaofeng, an actor who is also the ambassador of a green commuting campaign, offered his support to adopting a low-carbon lifestyle in China. His message echoed Xie's statement that China "will maximize its efforts to fight climate change and shoulder due responsibilities in line with its development stage".

"Domestically, we're studying what our mitigation efforts should look like after 2020," Xie said, adding that negotiations for the post-2020 targets should be based on the results of a review to be published in 2015.

The review should look at how industrialized countries' pledges under the Kyoto Protocol were accomplished and include an update of the climate science, he said.

China's stance is supported by three other emerging economies: Brazil, India and South Africa, which are also in the process of industrialization and have contributed little to historical greenhouse gas emissions.

Studies by leading climate experts from the four countries found that developing countries should have both equitable access to sustainable development and a period of time for them to lift people out of poverty.

The industrialized countries that ratified the Kyoto Protocol contributed to 90 percent of the global temperature rise between 1850 and 1990 because of their carbon emissions, according to a Brazilian study.

It states that these countries already have huge deficits in their carbon budgets.

"Our study shows that developed countries have far exceeded their fair share in carbon (emissions)," Girish Sant, an energy and environment researcher in India, told China Daily.

Zhang Yongsheng, a senior research fellow at the Development Research Center of the State Council, said carbon equity is key to addressing the issue of global warming.

"Our studies are not designed for the interests of any particular country, but for the global carbon equity," he said, adding that his study concluded that China's carbon budget is "obviously insufficient".