The UN climate talks have entered the "crucial stage" after two draft texts were proposed by the chairs of the two major working groups of the UN climate change conference in Copenhagen, China's chief negotiator in climate talks said Saturday.

Su Wei was speaking a day after the working groups on long term cooperative action under the United Nations Framework Convention on Climate Change and on the Kyoto Protocol put forward their draft decision papers.

"The draft texts show that we are moving forward in our negotiations. We welcome the emergence of the draft papers," Su told a press briefing.

The emergency of draft texts indicated the talks had entered "a crucial stage," he said.

Government ministers arriving in Copenhagen have a week to work for agreement on the two draft texts before 110 heads of state and government convene here to agree on goals to avoid irreversible change in climate that scientists warn could be disastrous to the Earth.

The draft texts endorse goals to keep global average temperature increase within "1.5 degrees" or "2 degrees." The texts also commit developed nations to reductions of greenhouse gas emissions by "75-85," "at least 80-95," or "more than 95" percent from 1990 levels by 2050. These options, bracketed in the texts, are yet to be agreed on.