Negotiators at deadlocked UN climate talks said Wednesday that rich countries have been urged to commit as much as $900 billion per year to help poorer nations take action against global warming. 

With two days left at the COP29 conference in Azerbaijan, countries are scrambling to bridge their differences over money seen as crucial for the world to curb planet-heating emissions.

Developing nations, which are least responsible for global emissions, say rich historic polluters have a duty to help pay for their green transitions and the devastating impacts of climate change.

While developed nations have yet to put any figures on the table, some developing countries have called for $1.3 trillion in annual funds.

Rich countries, which are facing tighter budgets and political pressures back home, insist that any commitment must also include loans and private money.

They also want countries such as China and Saudi Arabia, which have become wealthy but are still listed as developing nations, to contribute to climate finance.

Australian climate minister Chris Bowen, one of two envoys mediating the finance negotiations, said three different figures were suggested for the money that would come from the budgets of developed nations: $440 billion, $600 billion and $900 billion.

"Many parties told us they need to see certain building blocks in place before they can put forward their suggested number," Bowen told COP29 delegates.

Delegates from several countries told AFP the figures were not proposed by developed nations.

Bowen said some countries had drawn a "red line" over the type of money, insisting it come "from a wide range of sources and instruments".

Bolivia's chief negotiator, Diego Pacheco, said there was a "steadily receding hope of getting an ambitious" deal on climate finance.

"We are also hearing in the corridors figures of 200 billion being offered by our partners" on climate finance which would also include contributions from multilateral development banks, Pacheco said.

Buried in debt, developing nations insist that any deal should not include more loans.

"Only 200 billion," he told the conference. "This is unfathomable, we cannot accept this."

The lead negotiator of COP29 hosts Azerbaijan, Yalchin Rafiyev, urged countries to "pick up the pace" of negotiations and said a new draft deal would be released at around midnight on Wednesday.

"Let us embrace the spirit of collaboration, compromise and determination to ensure that we leave this conference with outcomes that make a real difference," he said.