"I exchanged views with my European colleagues before I came here and told them very clearly that a mandate is too much," Li Gao, speaking on the sidelines of the 12-day negotiations, told AFP late Tuesday.
Under the European Union's scheme, advanced economies including the United States and emerging giants China, India and Brazil would pledge to hammer out a comprehensive agreement within four years, to be implemented no later than 2020.
Without this, Europe says, the risk goes up of crossing the danger threshold of a 2.0 degree Celsius (3.6 degree Fahrenheit) increase in global temperatures.
Hoping to coax developing countries into the deal, the EU says it is willing to renew CO2-reduction pledges under the embattled Kyoto Protocol, whose first round of cuts expires next year.
Developing countries have come into the meeting under the UN Framework Convention on Climate Change (UNFCCC) demanding that Kyoto be kept alive.
But for China, an agreement to hammer out a global climate deal already exists.
The so-called Bali Roadmap in 2007 was supposed to conclude with a planet-saving pact in Copenhagen two years later.
Instead, that 2009 meeting deadlocked, barely avoiding collapse by producing an 11th-hour agreement that fell far short of the intended goal.
"We are still on the process of the Bali Roadmap. We have to finish our mandate and then we can talk about a new one," Li said.
"If we still have not finished, what should we do? We can't talk about something new, this is not a good way to proceed."
Li said China, the world's No. 1 carbon emitter, would not revisit targets through 2020 for slowing the increase of its greenhouse gas pollution by boosting energy efficiency.
But after 2020, Beijing would be ready to take on more ambitious mitigation goals, the legal character of which remains an open question, he added.
"We envisage that we will become more developed at that stage, we will contribute more to the global efforts on climate change -- that's for sure," he said.
"But it doesn't mean, at this stage, that will prejudge what will happen, what kind of target, or what kind of legal nature for that target."
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