Brazilian President Luiz Inacio Lula da Silva warned Tuesday the COP29 climate talks in Azerbaijan "cannot leave" the hard decisions on combating global warming to next year's meeting in Brazil.

"We cannot leave the task of Baku (Azerbaijan's capital) until Belem," Lula told the G20 summit underway in Rio de Janeiro, referring to the Amazonian city that will host next year's UN climate talks.

Negotiators in Baku had been hoping for a breakthrough at the G20 summit on issues blocking progress at their concomitant talks thousands of miles away.

But a statement from the meeting of world leaders in Rio fell short of expectations.

While acknowledging the need for trillions of dollars in climate finance for poorer nations the G20 statement failed to explicitly mention the need to transition away from fossil fuels.

Lula said that the 2025 COP summit would be the "last chance" to avoid "irreversible" damage wrought by Earth's warming.

Brazil is still reeling after its worst wildfire season in over a decade, triggered by a record drought blamed at least partly on climate change.

"Even if we do not cut down any more trees, the Amazon will continue to be threatened if the rest of the world does not fulfill its mission to tackle global warming," Lula said.

In what was seen as a swipe at US President-elect Donald Trump he warned that there was "no room for denialism" in what he billed as a "fight for survival."

With just three days left at the COP29 conference, he said: "I am counting on everyone to make Belem the COP of change."