Negotiations for a climate deal spilled into overtime at the COP28 summit in Dubai on Wednesday, as nearly 200 countries sought to bridge divisions on the future role of fossil fuels — by far the most contentious issue.

Where the two-week conference lands on the issue will send a powerful message to global investors and markets about the ambition of governments around the world to end the use of oil, gas and coal, or preserve place them.

Many nations had criticised a deal draft released on Monday for failing to call for a "phase-out" of fossil fuels, which scientists say are by far the biggest source of the greenhouse gas emissions driving global warming.

More than 100 countries ranging from the United States and the EU to tiny island nations like Samoa had pushed for the language but faced resistance from members of the OPEC oil producer group and its allies.

Late on Tuesday and into the early hours of Wednesday, country delegations met with each other and with the United Arab Emirates' COP28 host — which is responsible for writing a new draft of the final deal — to make clear their demands in a flurry of midnight shuttle diplomacy.

U.S. Special Climate Envoy John Kerry popped out of one meeting with representatives from several other delegations late on Tuesday and said he believed the fossil fuel language in the COP28 deal text was getting stronger.

"I think there’s progress and moving in the right direction," he told reporters. "And you know, we’re going to keep working through the night."

Toeolesulusulu Cedric Schuster, Samoa's environment minister, said "there are improvements from yesterday's language in some areas," but declined to offer specifics.

Small island nations, who are already feeling the brunt of climate-drive sea level rise, had described the Monday draft deal as a death sentence.

The COP presidency had hoped to wrap the two-week summit up by Tuesday morning, but clashes over the draft deal text forced negotiations into overtime - a routine pattern for the annual COP summits.

COP28 Director General Majid Al Suwaidi said the aim of the Monday text was to draw negotiators to reveal their demands and move the discussion forward.

"By releasing our first draft of the text, we got parties to come to us quickly with those red lines," he said.

Al Suwaidi said the COP28 presidency was aiming for a "historic" result that included mentioning fossil fuels - but that it was up to countries to agree.

The U.N. climate body that runs the COP process issued a notice early Wednesday saying new deal texts could be published at 0200 GMT, followed by a plenary session with the COP28 president at 0530 GMT.

OPEC PRESSURE

In a Dec. 6 letter seen by Reuters, OPEC Secretary General Haitham Al Ghais urged members and allies to reject any COP28 deal that targeted fossil fuels.

Negotiators and observers in the COP28 talks said that while Saudi Arabia has been the strongest opponent of anti-fossil fuel language in the text, other OPEC and OPEC+ members, including Iran, Iraq and Russia, have also resisted a fossil fuel phase-out deal.

"I'm worried ... because it's very obvious that we need more ambition," Denmark's Global Climate Minister Dan Jorgensen said. "I haven't given up yet of course, we still think this is possible."

The Monday draft had also been criticised as too weak by Australia, Canada, Chile, Norway and scores of others.

Some African nations, meanwhile, have said any deal must require wealthy countries, who have long produced and used fossil fuels, to quit first.

"The transition should be premised on differentiated pathways to net zero and fossil fuel phase-down," said Collins Nzovu, minister of Green Economy for Zambia, which chairs the African Group of countries in U.N. climate talks.

"We should also recognise the full right of Africa to exploit its natural resources sustainably," he added.

It was unclear if China, the world's top greenhouse gas emitter, supported Monday's draft. Its veteran climate change envoy, Xie Zhenhua, said progress was being made in the talks.

Two weary negotiators leaving the COP venue near midnight on Tuesday said the EU and others had rejected draft deal text concerning carbon markets.

The COP28 presidency is now expected to push the discussions concerning government-to-government carbon trades and the development of an international trading system into next year. The presidency was not immediately available to comment.

(Reporting by Valerie Volcovici, Kate Abnett, Jake Spring, Gloria Dickie, Elizabeth Piper, David Stanway; Editing by Richard Valdmanis and Lisa Shumaker)