UN Secretary-General Antonio Guterres has stressed the need to financially support Pacific island nations facing rising sea levels and other challenges brought by climate change.

Leaders of 18 countries and territories that make up the Pacific Islands Forum opened their annual meeting in Tonga on Monday.

Guterres said in a speech on Tuesday: "The world must look to the Pacific and listen to science. This is a crazy situation. Rising seas are a crisis entirely of humanity's making."

The UN and the World Meteorological Organization released a report on rising sea levels on Tuesday.

The report says while the change in global-mean sea level from 1993 to 2023 was plus 9.4 centimeters, the sea level rise in the tropical Pacific over the same period was greater than 15 centimeters in some locations.

Pacific island nations are frequently hit by tropical cyclones, and their low-lying areas near the shore are prone to flooding.

These nations need funding to deal with the impact of climate change, such as building levees and raising the ground.