A draft of a potential climate deal at the COP28 summit on Monday suggested a range of options countries could take to reduce greenhouse gas emissions, but omitted the "phase out" of fossil fuels many nations have demanded.

U.N. Secretary General Antonio Guterres said a central benchmark of success for COP28 would be whether it yielded a deal to phase out coal, oil and gas use fast enough to avert disastrous climate change.

"That doesn't mean that all countries must phase out fossil fuels at the same time," he told reporters at the Dubai summit, which is scheduled to end on Tuesday but could go on longer if negotiations drag on.

A new draft of a COP28 agreement, published by the United Arab Emirates' presidency of the summit, proposed various options but did not refer to a "phase out" of all fossil fuels, which had been included in a previous draft.

The draft deal listed eight options that countries "could" use to cut emissions, including by: "reducing both consumption and production of fossil fuels, in a just, orderly and equitable manner so as to achieve net zero by, before, or around 2050".

Other actions listed included tripling renewable energy capacity by 2030, "rapidly phasing down unabated coal" and scaling up technologies including those to capture CO2 emissions out of the atmosphere.

One European diplomat told Reuters the new text was weak on ambition and read like a "menu where you can pick and choose your dish at will".

A coalition of more than 100 countries including oil and gas producers the United States, Canada and Norway, as well as the European Union and climate-vulnerable island nations, wanted an agreement that included language to phase out fossil fuels, a feat not achieved in 30 years of the U.N. summits.

The emissions from burning fossil fuels are by far the main driver of climate change.

Canadian Environment Minister Steven Guilbeault told Reuters a deal on phasing out fossil fuels was being opposed by OPEC.

"We're the fourth largest oil and gas producer. We get it. It's complicated. It's unnerving. It creates uncertainty in parts of our country. But it's not a reason not to do it," Guilbeault said.

CONSENSUS NEEDED FOR ANY DEAL

For oil-producing nations, a global deal at COP28 to ditch fossil fuels - even without a firm end date - could signal a political willingness from other nations to slash their use of the lucrative products on which fuel-producing economies rely.

Speaking in a gathering of ministers and negotiators on Sunday, a representative for Saudi Arabia's delegation said a COP28 deal should not pick and choose energy sources, but should instead focus on cutting emissions.

"We have raised our consistent concerns over the attempts to attack energy sources instead of emissions," the representative said.

That position echoes a call made by OPEC in a letter to its members earlier in the COP28 summit, seen by Reuters, which asked them to oppose any language targeting fossil fuels directly.

Deals at U.N. climate summits must be passed by consensus among the nearly 200 countries present. That high bar aims to establish a consensus on the world's next steps to tackle climate change, which individual countries should then make happen through their national policies and investments.

Developing nations have said any COP28 deal to overhaul the world's energy system must be matched with sufficient financial support to help them do this.

"We need support as developing countries and economies for a just transition," said Colombia's Environment Minister Susana Muhamad said. Colombia supports a COP28 deal to phase out fossil fuels.

"But the first step is the COP, because we should send here the strong political message that this is the pathway," she told a press conference.

Despite the rapid growth of renewable energy, fossil fuels still produce around 80% of the world's energy.

Negotiators told Reuters that other OPEC and OPEC+ members including Russia, Iraq and Iran, have also resisted attempts to insert a fossil fuel phase-out into the COP28 deal.

(Reporting by Kate Abnett, Valerie Volcovivi, David Stanway, Sarah McFarlane, Maha el Dahan, Elizabeth Piper, Gloria Dickie; Editing by Katy Daigle, Sonali Paul, Timothy Heritage, Nick Macfie and Alex Richardson)