An influential alliance including several European countries and Pacific island states backed the global phaseout of fossil fuels, potentially pitting them against China in what is set to be a central debate at this year's COP28 climate summit.
The High Ambition Coalition - which counts the Marshall Islands, Tuvalu, Samoa, Vanuatu, Austria and France among its members - called for a decline in fossil fuel production and use.
Bloomberg reported that the nations also say a decision at the summit should include ending both new coal production and the expansion of existing mines, as well as reducing methane emissions to near zero.
The US and members of the European Union have often clashed with developing countries - notably China - over the steps needed to curb climate change, as the latter group hasn't had the benefit of more than a century of unfettered industrialisation.
Washington didn't sign a statement from the coalition.
Whether they can find common ground will determine the outcome of the upcoming United Nations' Conference of the Parties, known as COP, in Dubai.
A key component of the summit is the Global Stocktake, where countries tally how close they are to the goal of keeping global warming below 1.5C - and ideally chart what needs to be done to close the gap.
"Fossil fuels are at the root of this crisis," the High Ambition Coalition said in a statement. "We must phase out all international public finance for fossil fuel development and power generation."
The alliance also said governments must demand that oil, gas and coal producers publish "trackable transition plans that set out how they'll cut emissions by 2025, and reach net zero by 2050."
Crucially, the countries also laid out a narrow vision for how so-called abatement technologies, like carbon capture and storage, should be used during the transition. They only have "a minor role to play" and should "not be used to delay climate action," the coalition said. The language is stronger than the EU's negotiation mandate agreed earlier this month.
COP28 takes place from 30 November to 12 December, and the run-up has already been marred by growing geopolitical tensions, with the Israel-Hamas war coming on top of Russia's invasion of Ukraine.
Climate negotiations have also stalled amid disputes over the extent to which fossil fuels should be phased out and how to establish a fund to cover the losses and damages caused by increasingly extreme weather.