The Brazilian initiative follows last November's COP30 summit in the Amazon city of Belem, which concluded with a deal that lacked any explicit mention of fossil fuels after opposition from major producers Saudi Arabia and Russia.

As a consolation, COP30 president Andre Correa do Lago offered to push for a separate, voluntary roadmap away from fossil fuels for countries willing to join.

In a letter obtained by AFP on Friday, Correa do Lago said he asked the UN's climate body to forward an invitation for countries and organisations to submit proposals by March 31.

The diplomat acknowledged that the initiatives are not mandated by the official COP negotiations.

But he added: "I am firmly convinced that they must be pursued in an inclusive, participatory, and transparent manner, and that these roadmaps can help us identify practical options for implementing the goals we have already agreed."

More than 190 countries agreed to transition away from fossil fuels at the COP28 meeting in Dubai in 2023, but little progress has been made on the issue since then.

Colombia will host in April an international conference on moving away from fossil fuels, the main drivers of climate change.

In November, Turkey is hosting the next UN climate summit, COP31, with Australia leading the negotiations.

The Brazilian letter asks countries to identify "critical barriers" -- including economic, financial or technological -- preventing a transition away from fossil fuels and a reversal of deforestation.

It also invites countries to suggest economic, social and technological levers to accelerate the shift away from fossil fuels and halt deforestation.

Speaking to reporters earlier this month, Correa do Lago said: "We will see if ... the issue can go into the COP31 agenda."