Vice-Premier Li Keqiang (right) meets with US climate change envoy Todd Stern in Beijing on Monday. [Rao Aimin]

While a "major breakthrough" appears to have eluded China and the United States in the latest bilateral climate change talks that will end Wednesday in Beijing, the world's largest emitters did promise to strengthen scientific cooperation in the fight against global warming.

The two nations made sure the talks were low-key and expectations were not too high and little was said about talking points and expectations before the three-day meeting attended by US climate change envoy Todd Stern.

However, a source familiar with both negotiating teams told China Daily that Stern and his delegation met Chinese climate change envoy Xie Zhenhua twice on Monday.

"As far as I know, the two sides showed intent to start a partnership on climate change cooperation at an early stage but, so far, they have achieved only limited progress and it is mainly shown in scientific cooperation," the source said.

Vice-Premier Li Keqiang met the US delegation on Monday and pledged to strengthen Sino-US cooperation on climate change and clean energy technologies.

The source said the "limited progress" did not mean there was a failure between the two countries; the nations will have more opportunities to make further progress before the international community hammers out a deal in Copenhagen in December.

Some developed countries have been slow to provide emission targets, while others have set targets that are lower than the requirements of the international community, Li said.

Li took the US as an example, saying the country had delayed its greenhouse gas reduction obligation for 20 years.

To push forward the agenda, China recently made its position clear ahead of the Copenhagen talks and asked developed countries to cut emissions by at least 40 percent from 1990 levels by 2020.

On the subject of climate-friendly technology and funding, Li said, developed countries failed to fulfill their obligations during the past decade.

In another development, Greenpeace, WWF International and four non-government groups have called upon 10 newly industrialized countries including Singapore, Saudi Arabia and South Korea to voluntarily adopt binding greenhouse-gas emissions targets. The countries have exemption from setting mandatory targets until 2013.

Larger developing countries including Brazil, China and India do not have to take on binding goals.

The environmental organizations are calling on wealthier nations to commit to almost eliminate greenhouse gases by 2050, with a 40 percent reduction from 1990 levels by 2020.

The groups said rich countries should also channel $160 billion per year to less-wealthy countries to help them adapt.