LIMA: Negotiations on forging a UN pact to fight climate change headed into an unscheduled 13th day on Saturday in a frantic quest to bridge a rift between rich and poor countries.

Ministers and senior officials from 195 states were to examine a compromise for calming a bustup over who bears responsibility for fighting climate change. The talks in Lima had been scheduled to end at 6:00 p.m. (2300 GMT) Friday, but ran into the pre-dawn as countries horse-traded over elements of a draft text.

Exhausted delegates were then given the chance of a few hours’ sleep before a meeting at 1500 GMT Saturday to sound out opinion in a working group tasked with finalizing the big document.

On the table is a text for shaping a worldwide accord to roll back carbon pollution which is now on track to ravage Earth’s climate system.

Theoretically sealed in Paris in December 2015 and taking effect by 2020, the deal would for the first time bring all members of the UN Framework Convention on Climate Change (UNFCCC) into a single arena for cutting greenhouse gases.

Its objective would be to ratchet down annual gas emissions so that global warming, driving climate shift, would never exceed two degrees Celsius (3.6 degrees Fahrenheit) over pre-industrial levels.