There is no mention of "fossil fuels" in the latest slimmed down text proposal, released on the final day of the major UN climate conference in the rainforest city of Belem.

Around 30 countries had written to the Brazilian presidency on Thursday warning they could not accept a final deal that did not include a plan for moving away from fossil fuels.

The European Union's climate commissioner Wopke Hoekstra said in a statement to AFP he was "disappointed" with the latest text.

"This is in no way close to the ambition we need on mitigation. We are disappointed with the text currently on the table," he said.

Brazil's President Luiz Inacio Lula da Silva has put his support behind the call for a global roadmap away from coal, oil and gas, which are the primary drivers of global warming.

But the proposal is opposed by a group of mainly oil-producing nations, and consensus is needed among the nearly 200 nations at the climate talks to land an agreement.

Divisions remain not just over fossil fuels but trade measures and finance for poorer nations to adapt to climate change and move to a low-carbon future.

Negotiations toward a final outcome were delayed on Thursday when a fire erupted in the COP30 venue, forcing thousands to evacuate at a crucial phase in the talks.

The conference is supposed to end on Friday but the climate summits often run into overtime.