LE BOURGET, France (AP) — With only hours left to produce a global climate accord, rifts emerged Friday between Western countries and China and its allies over how to share the burdens of reducing carbon pollution and helping vulnerable nations cope with the rising seas and extreme weather that comes with global warming.

The issue has dogged climate negotiations for years and diplomats at the talks now underway outside Paris are hoping it won't threaten a long-awaited deal. U.N. Secretary-General Ban Ki-Moon, U.S. Secretary of State John Kerry and other top officials shuttled among high-stakes meetings all day Friday in hopes of coming to a final agreement on Saturday.

China's deputy chief negotiator stood firm Friday on his nation's demand that rich countries should assume most responsibility for the costs and argued against an agreement that sets too-tough goals for weaning the world off using oil, gas and coal — the biggest source of carbon emissions.

The talks, originally scheduled to end Friday, dragged into an extra day as the French hosts said they needed more time to overcome disputes.

Negotiators from more than 190 countries are aiming to create something that's never been done before: an agreement for all countries to reduce man-made emissions of carbon dioxide and other greenhouse gases and helping the poorest adapt to rising seas, fiercer weather and other impacts of global warming.

The U.S. and European countries want to move away from so-called "differentiation" among economies and want big emerging countries like China and India to pitch in more in a final climate deal.

But Liu Zhenmin, deputy chief of the Chinese delegation, told reporters Friday that issue is "at the core of our concern for the Paris agreement." He said he wants different rules for different countries "clearly stipulated" in the global warming pact, and insisted the demand is "quite legitimate."

China is among the more than 180 countries that have submitted emissions targets for the new pact but is resisting Western proposals for robust transparency rules that would require each country to show whether it's on track to meet its target.

Liu also argued against sharply limiting the number of degrees the planet warms this century, because that would involve huge lifestyle and economic changes.

"We need heating. We need air conditioning. You need to drive your car," he said.

Indian Environment Minister Prakash Javadekar also said differentiation was the biggest dispute and accused developed countries of not showing enough flexibility in the talks.

However, signs of divisions among major developing countries surfaced Friday as Brazil joined an informal coalition of Western countries and some developing ones in a "high-ambition coalition" that is calling for a strong deal.

Liu dismissed the coalition as a "performance."

Kerry, on his fifth straight day in France trying to iron out differences with developing countries, said he's "hopeful" for an accord and has been working behind the scenes to reach compromises.

U.S. climate envoy Todd Stern said U.S. negotiators have been having lots of talks with India, saying "hopefully we're making some progress."

The two weeks of talks are the culmination of years of U.N.-led efforts to create a long-term climate deal. U.N. climate conferences often run past their deadlines, given the complexity and sensitivity of each word in an international agreement and the consequences for national economies.

Analysts said the delay until Saturday was not necessarily a bad sign.

"This needs consensus," said Michael Jacobs, an economist with the New Climate Economy project, speaking to reporters outside Paris. "There's a lot of negotiating to do."

Sam Barratt of the advocacy group Avaaz said getting 200 countries to agree on anything is quite difficult.

"Getting them to agree on the future of the planet and a deal on climate change is probably one of the toughest pieces of negotiation they'll ever get involved in," Barratt said.

This accord is the first time all countries are expected to pitch in — the previous emissions treaty, the 1997 Kyoto Protocol, only included rich countries.

The latest 27-page draft said governments would aim to peak the emissions of heat-trapping greenhouse gases "as soon as possible" and strive to reach "emissions neutrality" by the second half of the century — a vague term generally understood to mean no more emissions than the Earth can naturally absorb. That was weaker language than in previous drafts, which included more specific emissions cuts and timeframes.

China's Liu said negotiators don't understand what is meant by "neutrality" and argued for an even softer "low-carbon" goal.

The draft didn't resolve how to deal with demands from vulnerable countries to deal with unavoidable damage from rising seas and other climate impacts. One option said such losses would be addressed in a way that doesn't involve liability and compensation — a U.S. demand.

French Foreign Minister Laurent Fabius, who was expected to present a new draft Saturday morning, said the world would not find a better moment to reach a global climate deal.

"All the conditions are met to reach a universal, ambitious agreement," Fabius said.