A group of conflict-affected countries is pushing at COP29 to double financial aid to more than $20 billion a year to combat the natural disaster and security crises facing their populations, a letter seen by Reuters showed.

A group of former leaders and climate experts said the annual U.N. COP climate talks were no longer fit for purpose and needed to be reformed, publishing a critical open letter mid-way through what has so far been a fractious summit.

Countries at the COP29 summit tried to make progress on how to raise up to $1 trillion in climate finance for the world's most vulnerable, as political tensions overshadowed the talks and Argentina on Thursday pulled its delegation from Baku.

At the United Nations climate talks in Baku, Azerbaijan, wars are top of mind for some leaders and activists who have converged to discuss ways to limit global warming.

"You owe us!" screamed a protest banner at the COP29 summit in Azerbaijan, where negotiations over how much rich nations most responsible for climate change should pay poorer ones are

Developing countries need at least $1 trillion per year by the end of the decade to cope with climate change, economists told U.N. talks in Baku, where early efforts to reach a finance deal risk being overshadowed by diplomatic rows.