Delegates to the UN climate talks in Lima, Peru, pressed on with negotiations into the night Saturday, after developing countries rejected a draft agreement they say would unfairly allow rich nations to avoid their responsibility to curb climate change.

Negotiators thus far have failed to reach an agreement on what information should go into the pledges that countries plan to submit at a global climate summit in Paris next year. The aim of the pledges is to limit average global warming to two degrees Celsius (3.6 degrees Fahrenheit) over pre-Industrial Revolution levels by cutting carbon emissions.

Developing nations have demanded that the West take on a bigger share of the burden for carbon cuts, reasoning that they started to pollute the environment decades ago.

However, wealthy nations were quick to point out that fast developing economies like China and India are guilty of burning fossil fuels to power their rapid growth.

"We have deadlock," said Chinese negotiator Liu Zhenmin, whose country called the draft deal inequitable.

US negotiator Todd Stern said he was open to adjusting the language in the draft deal, but did not want to get involved in protracted negotiations.

"Failing to produce the decision before us will be seen as a serious breakdown," said Stern, adding that such a failure could put the upcoming Paris agreement and the entire UN climate negotiations at risk.

The United States urged the more than 190 nations participating in the summit to approve the draft deal. US Secretary of State John Kerry said Thursday that fixing the problem was "everyone's responsibility, because it's the net amount of carbon that matters, not each country's share."

bw/cmk (AP, dpa)