The head of China's delegation to the UN climate talks taking place in Peru is describing a new pledge of some 10 billion US dollars by developed nations as, perhaps, "far from adequate."

Su Wei says the total pledge of 9.7-billion US dollars to a new UN Green Climate Fund designed to help developing nations cope with climate change is only a small part of the cash needed.

"The objective for 2020 is the provision of 100 billion US dollars per year by 2020, so 10 billion is just one tenth of that objective. Yet we do not have any clear roadmap or clear picture of meeting that target by 2020. Of course the 10 billion is not for a year, even. It applies to initial capitalization of the Green Climate Fund. That's why I said it is maybe far from adequate."

The current talks in Lima are meant to try to create a framework agreement for a new climate change deal to be signed in Paris in a year's time.

The two weeks of talks in South America follow an agreement between China and the US worked out last month.

As part of that deal, China has agreed to put a cap on its carbon emissions by 2030.

China has also agreed to make zero-carbon energy account for 20 percent of the country's total during the same time-frame.

The US side is promising to cut its own emissions by more than a quarter by 2025.