The tightest of smiles on his face and the fabric of his traditional thobe swirling about him as he strides through a hallway at U.N. climate talks, Saudi Arabia’s energy minister expresses shock at repeated complaints that the world’s largest oil producer is working behind the scenes to sabotage negotiations.

“What you have been hearing is a false allegation, and a cheat and a lie,” Prince Abdulaziz bin Salman al Saud said this week at the talks in Glasgow, Scotland. He was responding to journalists pressing for a response to claims that Saudi Arabia’s negotiators have been working to block climate measures that would threaten demand for oil.

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“We have been working well” with the head of the U.N. climate talks and others, Prince Abdulaziz said.

Negotiators from about 200 countries are coming up against a weekend deadline to find consensus on next steps to cut the world’s fossil fuel emissions and otherwise combat climate change.

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Saudi Arabia’s participation in climate talks itself can seem incongruous — a kingdom that has become wealthy and powerful because of oil involved in negotiations where a core issue is reducing consumption of oil and other fossil fuels. While pledging to join emission-cutting efforts at home, Saudi leaders have made clear they intend to pump and sell their oil as long as demand lasts.

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Saudi Arabia’s team in Glasgow has introduced proposals ranging from a call to quit negotiations — they often stretch into early morning hours — at 6 p.m. every day to what climate negotiation veterans allege are complex efforts to play country factions against one another with the aim of blocking agreement on tough steps to wrench the world away from coal, gas and oil.

That is the “Saudis’ proposal, by the way. They’re like, let’s just not work at nights and just accept that this is not going to be ambitious” when it comes to fast cuts in fossil fuel pollution that is wrecking the climate, said Jennifer Tollmann, an analyst at E3G, a European climate think tanks.

And then “if other countries want to agree with Saudi, they can blame Saudi Arabia,” Tollmann said.

Saudi Arabia long has been accused of playing a spoiler in the climate talks, and this year it is the main country singled out so far by negotiators, speaking privately, and observers, speaking publicly. Russia and Australia are also lumped in with Saudi Arabia at the talks as countries that see their futures as dependent on coal, natural gas or oil, and as working for a Glasgow climate deal that doesn’t threaten that.

Despite efforts to diversify the economy, oil accounts for more than half of Saudi Arabia’s revenue, keeping the kingdom and royal family afloat and stable. About half of Saudi employees still work for the public sector, their salary paid in large part by oil.

And there’s China, whose dependence on coal makes it the world’s current biggest climate polluter. It argues it can’t switch to cleaner energy as fast as the West says it must, although the United States and China did jointly pledge to speed up their efforts to cut emissions.

A core issue in the talks: Scientists and the United Nations say the world has less than a decade to cut its fossil fuel and agricultural emissions roughly in half if it wants to avoid more catastrophic scenarios of global warming.

Not surprisingly, island nations that would disappear under the rising oceans at a higher level of warming are the bloc at Glasgow pushing hardest for the most stringent deal out of this summit.

Meanwhile, climate advocates accuse the United States and European Union of so far failing to throw their weight behind the demands of the island nations, although the U.S. and E.U. often wait until the last few days of climate talks to take hard stands on debated points.

The United States — the world’s worst climate polluter historically and a major oil and gas producer — gets plenty of criticism in its own right. The Climate Action Network dishonored the Biden administration with its “Fossil of the Day” award to President Joe Biden for coming to Glasgow last week with ambitious climate talk — but failing to join a pledge to wean his nation off coal, or to rein in U.S. oil production.

Jennifer Morgan, executive director of the Greenpeace environmental group, said other governments need “to isolate the Saudi delegation” if they want the climate conference to succeed..

Saudi Arabia was fine with joining in governments’ climate-pledge fever before the talks. Saudi Crown Prince Mohammed bin Salman announced in the runup to Glasgow that the kingdom would zero out its carbon emissions by 2060.

But Saudi leaders for years have vowed to pump the last molecule of oil from their kingdom before world demand ends — an objective that a fast global switch from fossil fuels would frustrate.

“Naked and cynical,” says Alden Meyer, a senior associate at the E3G climate research group, of Saudi Arabia’s role in global climate discussions.