Ana Toni told AFP that Brazil wanted to spur a global "debate" about how to turn a promised fossil fuel phasedown into action, including through possible taxes on coal, oil and gas.

"This should be a just transition on stopping fossil fuels," Toni, who is Brazil's national secretary for climate change, said in an interview on the sidelines of the COP29 summit in Azerbaijan.

"We will never shy away from those very important discussions because it is in our own interests."

COP30 will be the third consecutive year the UN's top climate talks have been held in a country that plans to expand domestic production of fossil fuels.

Brazil is the largest oil producer in Latin America, and its COP30 comes after COP29 in Azerbaijan and last year's COP28 in the United Arab Emirates.

Some high-profile climate leaders last week called for COPs to no longer be held in countries that do not support phasing out their own production of fossil fuels, the main driver of global warming.

Toni, who has held senior advisory roles with Greenpeace and ActionAid, said Brazil had always been a climate champion and would keep "leading by example".

"We were the first ones to say, let us stop deforestation. The same we'll do with fossil fuels," said Toni, who is also heading Brazil's delegation at COP29.

"But that agreement needs to be together with the other countries, and Brazil will play a very, very strong role in pushing to get the other countries to do so."

- Nothing to prove -

In a landmark moment, nearly 200 countries agreed last year at COP28 to transition away from fossil fuels.

But the burning of coal, oil and gas hit record highs in 2024 and efforts to advance the transition away from fossil fuels have hit political opposition at this year's COP.

Toni said Brazil shared similar "contradictions" to the United States and Norway, both fossil fuel producers who also advocate cuts to planet-heating emissions.

She said Brazil, which plans to host the COP30 in the Amazonian city of Belem, was pushing nations to consider how to address fossil fuel use through taxes or ending subsidies.

Ahead of COP30, all nations are supposed to submit updated plans for slashing their emissions of greenhouse gases.

Last month, the UN said current national plans fell "miles short" of what was needed to avoid severe consequences of climate change.

Ahead of COP29, Brazilian President Luiz Inacio Lula da Silva's left-leaning government announced it would cut emissions more dramatically than had been planned.

Climate activists said Brazil did not go far enough, but Toni said it was the most ambitious plan of any developing country.

"We don't have anything to prove to anyone," she said.

Before COP30, Toni first must help break an impasse at COP29, where she has been appointed along with UK Energy Secretary Ed Miliband to land a successful financing deal by Friday when the summit is supposed to conclude.

She said failure to reach a deal on financing energy transitions and adaptations for developing countries could deflate global climate action right as Brazil prepares to take the reins.

"That's exactly what we don't want to happen. So the success of COP30 depends on the success of a good COP29," she said.