New Caledonia's Congress said a unanimous decision has been made to declare a climate emergency.
Its President Roch Wamytan said fires, drought and lack of water are now affecting lives and activities.
The Congress said it would work with the government, the provincial administrations, the French state, the European Commission and other institutions to attain a consensus without delay.
It said this is to adopt concrete measures to fight this threat before it is too late.
The New Caledonian government announced that it would hold a conference in March on climate and bio-diversity which would include civil society groups.
There have been hundreds of fires this year, destroying about 370 square kilometres of vegetation.
Mr Wamytan said the situation is a concern for everyone and no time must be lost.