French Foreign Minister Laurent Fabius presented a landmark global climate accord on Saturday, a "historic" measure for transforming the world's fossil fuel-driven economy within decades and turn the tide on global warming.

At the tail end of the hottest year on record and after four years of fraught U.N. talks often pitting the interests of rich nations against poor, imperilled island states against rising economic powerhouses, Fabius urged officials from nearly 200 nations to support what he hopes will be a final deal.

"Our responsibility to history is immense," Fabius told thousands of officials, including President Francois Hollande and U.S. Secretary of State John Kerry, in the main hall of the conference venue on the outskirts of Paris.

Barring any last-minute objections, negotiators will reconvene this afternoon to approve the agreement, a major breakthrough in global efforts to avert the potentially disastrous consequences of an overheated planet.

Fabius called it an "ambitious and balanced" agreement that would mark a "historic turning point" for the world. The official text of the accord would be made available within the next hour, he said.

In talks that lasted into the early morning on Friday, officials appeared to have resolved the final sticking points, and Fabius highlighted the key points: a more ambitious goal for limiting the rise in global temperatures to less than 2 degrees Celsius; a $100 billion a year floor for funding developing nations beyond 2020; and a five-year cycle for reviewing national pledges to take action on greenhouse gas emissions.

Prior to the session, China's top negotiator Gao Feng said there "there is hope today" for a final pact, while Marshall Islands Foreign Minister Tony De Brum told Reuters: "I think we're done here."

A deal, if finalised, would be a powerful symbol to world citizens and a potent signal to investors - for the first time in over two decades, both rich and poor nations will agree to a common vision for curbing greenhouse gas emissions, and a roadmap for ending two centuries of fossil fuel dominance.

While some climate change activists and U.S. Republicans will likely find fault with the accord - either for failing to take sufficiently drastic action, or for overreacting to an uncertain threat - many of the estimated 40,000 officials and environmentalists who set up camp on the outskirts of Paris say they see it as a long overdue turning point.

Six years after the previous climate summit in Copenhagen ended in failure and acrimony, the Paris pact appears to have rebuild much of the trust required for a concerted global effort to combat climate change, delegates say.