Durban, South Africa: The United Nations climate talks on Tuesday were mired in problems as environment ministers from around the world began a four-day huddle focused on the future of the Kyoto Protocol.

The US played down hopes for a deal with China that, by ensuring the survival of the threatened treaty, would lead to a breakthrough.

A file photo of Antarctica (Bloomberg)

“The Kyoto Protocol should be continued and a second commitment period is a must," China’s top climate negotiator Xie Zhenhua, speaking in the name of the BASIC group, said at a press conference.

“The most important issue for us in Durban is that a clear and ratifiable decision on a KP (Kyoto Protocol) second commitment period takes place. This must happen if KP parties are really committed to addressing climate change," said India’s environment minister Jayanthi Natarajan.

Hopes of movement were raised on Sunday when China signalled willingness—linked with conditions—to embrace a future legally-binding treaty on carbon emissions.

Green campaigners seized on this as a chance to remove one of the roadblocks to a deal that would save Kyoto, the only treaty that sets down legally-enforceable curbs on greenhouse gases.

But US chief delegate Todd Stern on Tuesday poured cold water on the Chinese position.

“It’s not my impression that there has been any change at all in the Chinese position with respect to a legally binding agreement," Stern told a press conference.

He said key details had to be answered in such a pact.

Kyoto is an icon for green campaigners and developing countries, which seize on it as an effective means to tame global warming and show solidarity between rich and poor nations.

But the Protocol’s future is clouded.

The first round of emissions pledges under Kyoto expires next year.

The EU has offered to sign up for a second round of commitments, but only if it secures approval for a “road map" leading to a new, legally binding pact that would encompass the big carbon polluters.

Stern downplayed the significance of “legally binding," saying it was not the “be all and end all" of solutions for climate change as its defenders suggested.

Instead, he promoted a deal endorsed in Cancun last year that uses a roster of voluntary emissions curbs, by 2020, to tackle greenhouse gases.