The World Bank is to make $200 billion available to fund action on climate change from 2021 to 2025, helping countries adapt to the effects of global warming and reduce greenhouse gas emissions.
The sum represents a doubling of the five-year investment plan put in place after the Paris agreement of 2015.
Jim Yong Kim, president of the World Bank, said the poorest and most vulnerable people were at the greatest risk, and urged other financial institutions to follow its lead.