Rich nations' pledges of almost $US10 billion ($11.9 billion) to a green fund to help poor nations cope with global warming are "far from adequate", particularly Australia's lack of a donation, the head of China's delegation at UN climate talks said on Thursday.

Su Wei also urged all rich nations to deepen their planned cuts in greenhouse gas emissions, signalling that a joint Chinese-US announcement of greenhouse gas curbs last month does not mean an end to deep differences on climate policy.

Prime Minister Tony Abbott hosting China's President Xi Jinping last month. Credit:Lukas Coch

Speaking during the December 1-12 talks in Lima, Mr Su said donor pledges last month totalling $US9.7 billion to a new UNGreen Climate Fund (GCF), to help developing nations cut emissions and adapt to climate change, were only a small part of needed cash.

"It is far from adequate," he told a news conference, noting that developed nations in 2009 agreed to mobilise $US100 billion a year from both public and private sources by 2020 to help poor nations suffering droughts, heat waves, floods and rising seas.