BAKU — The 29th United Nations Climate Change Conference, or COP29, opened on Monday in Azerbaijan with a call to show global cooperation was not "down for the count," as Donald Trump's reelection hangs over the key discussions.

Countries come to Azerbaijan's capital Baku after new warnings that 2024 is on track to break temperature records, adding urgency to a fractious debate over funding for climate action in poorer countries.

Trump has pledged to once again withdraw the United States from the landmark Paris climate agreement, and there are concerns the move could weaken ambition around the negotiating table.

As the talks opened, UN climate chief Simon Stiell told countries: "Now is the time to show that global cooperation is not down for the count."

And he warned wealthy countries that are struggling to agree on a new funding target to "dispense with any idea that climate finance is charity."

"An ambitious new climate finance goal is entirely in the self-interest of every nation, including the largest and wealthiest."

Negotiators must increase a $100 billion-a-year target to help developing nations prepare for worsening climate impacts and wean their economies off fossil fuels.

How much will be on offer, who will pay and who can access the funds are some of the major points of contention.

Developing countries are pushing for trillions of dollars, and insist money should be mostly grants rather than loans, but negotiators are tightlipped over what final figure might emerge.

COP29 President Mukhtar Babayev acknowledged the need was "in the trillions" but said a more "realistic goal" was somewhere in the hundreds of billions.

"These negotiations are complex and difficult," the former executive of Azerbaijan's national oil company said at the opening of the summit.

Developing countries warn that without adequate finance, they will struggle to offer ambitious updates to their climate goals, which countries are required to submit by early next year.

Few G20 leaders

The small group of developed countries that currently contributes the money wants the donor pool expanded to include other rich nations and top emitters, including China and the Gulf states.

That is firmly rejected by Beijing, with one Chinese official warning during a closed-door session on Sunday that the talks should not aim to "renegotiate" existing agreements.

Just a handful of leaders from the Group of 20, whose countries account for nearly 80 percent of global emissions, are attending. US President Joe Biden is staying away.

Afghanistan will, however, be sending a delegation for the first time since the Taliban took power. They are expected to have observer status.

Diplomats have insisted that the absences, and Trump's win, will not detract from the serious work at hand.

The talks come with fresh warnings that the world is far off track to meet the goals of the Paris agreement.

Babayev warned the talks were "a moment of truth for the Paris agreement."

The climate deal commits to keep warming below 2 degrees Celsius compared to pre-industrial levels, preferably below 1.5 C.

But the world is likely to top that level in 2024, the European Union's climate monitor said.

That would not be an immediate breach of the Paris deal, which measures temperatures over decades, but it suggests much greater climate action is needed.

Last month, the UN warned the world is on a path toward a catastrophic 3.1 C of warming this century based on current actions.