The pledge would be the biggest single funding commitment the UK has made to date to help the world tackle climate change, a government statement said.

The Green Climate Fund (GFC) – the world’s largest such fund – was set up under the United Nations climate change negotiations to help channel money needed by poor states to meet their targets to reduce carbon emissions, develop cleaner energy sources, and adjust to a warming world.

The UK has committed to spend US$14.46 billion on international climate financing between 2021 and 2026.

“Today’s pledge represents a 12.7% increase on the UK’s previous contribution to the GCF for the period of 2020-2023,” Sunak’s office said in a statement.

In July, the Guardian reported the country was planning to drop its flagship climate funding pledge, but the British government said those claims were false.

Government officials calculated it would have to spend 83% of the total aid budget on the international climate fund to meet the US$14.46 billion target by 2026.

The G20 nations adopted a wide-ranging declaration yesterday that included a reiteration of its commitment to scale up sustainable finance to help developing countries reduce their carbon footprints.

It said US$5.8-5.9 trillion is required by developing countries before 2030, in particular for their needs to implement their emission targets.