Diplomatic tensions over global warming will take center stage at the G20 summit in Brazil this week, as negotiators at U.N. talks in Azerbaijan hit an impasse on climate finance that they hope leaders of the world's 20 major economies can break.

Azerbaijani leader Ilham Aliyev has been praising fossil fuel and taking shots at geopolitical rivals, casting a cloud over the climate summit.

Negotiations were deadlocked Saturday at the midway point of the UN climate summit, with hopes pinned on G20 leaders intervening to strike a critical finance pact at the crunch talks.

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 disputes.

Half way through the UN climate conference, the UN climate chief looked ahead to the gathering of the Group of 20 (G20) powers and issued a dire warning about the outlook for the globe unless changes are made.

The UN's climate chief urged G20 leaders on Saturday to push COP29 talks towards a deal to raise money for developing nations as diplomats struggled to find common ground in

The plea, made in a letter to G20 leaders from top U.N. climate official Simon Stiell, comes as negotiators at the COP29 conference in Baku struggle for a deal intended to scale up money to address the worsening impacts of global warming.