DURBAN, South Africa – The European Union's conditions before signing a second commitment period of Kyoto Protocol are "not fair" for developing countries, but China is open to negotiation, China's leading climate negotiator, Su Wei, said on Tuesday.

The Kyoto Protocol, effective since 1997, is the only international treaty that sets binding greenhouse gas reduction targets for industrialized countries. And its first commitment period expires next year.

EU has said it will only extend targets under the protocol provided there will be a timetable for negotiating a single legally binding instrument joined by China and US.

"The new conditions are already beyond the mandate agreed in previous talks, namely the Bali Roadmap agreed in 2007," he said.

"I think EU is just shifting the goalpost from one place to another," Su said. "This is actually not an efficient way to do things, because we need to accomplish the goals one by one."

"But since EU is the group of countries who would seriously consider a second commitment period under the Kyoto Protocol, developing countries are also open and ready to talk to them about how to address that issue," said Su.

We hope "to secure a really effective and legally binding second commitment period of Kyoto Protocol," he said, calling the international treaty a "cornerstone" for climate talks.

And developing countries may refuse to sell carbon credits generated under the Clean Development Mechanism (CDM) to those nations who refuse to join a second commitment period of Kyoto Protocol, he added.

"The market mechanism was designed under Kyoto Protocol to help developed countries implement their emission reduction targets in the first commitment period," he said. "So if there is no target, why CDM?"