Construction of new coal-fired power plants should cease by next year and countries should introduce a price on carbon emissions in a bid to prevent "catastrophic" impacts from climate change, the United Nations Secretary General Antonio Guterres says.

Mr Guterres also used his address to the Pacific Island Forum in Fiji on Wednesday to call on nations to stop subsidising fossil fuels: "Taxpayer money should not be used to boost hurricanes, spread drought and heatwaves, melt glaciers, and bleach corals."

The UN chief is on a tour of Pacific Island states ahead of a week-long climate action summit in New York in September. The region's low-lying states, such as Vanuatu and Kiribati, are particularly vulnerable from rising sea levels as ice sheets in Greenland and Antarctica melt.

"Here in the Pacific, sea-level rise in some countries is four times greater than the global average and is an existential threat to some island states," he said in his speech.