The venue of COP29 in Baku, Azerbaijan. (Photo: Kyodo/VNA)

The agreement, clinched in overtime at the two-week conference in Azerbaijan's capital, was meant to provide momentum for international efforts to curb global warming in a year destined to be the hottest on record.

Under the agreement, only 300 billion USD per year is in grants or low-interest loans from developed countries. The remainder 1 trillion USD in climate finance would include funding from all public and private sources and tax collected from fossil fuels use.

Negotiations had been due to finish on Friday but ran into overtime as representatives from nearly 200 countries struggled to reach consensus. Talks were interrupted on Saturday as some developing countries and island nations walked away in frustration.

Countries also agreed on rules for a global market to buy and sell carbon credits that proponents say could mobilise billions more dollars into new projects to fight global warming, from reforestation to deployment of clean energy technologies.