Five island nations vulnerable to climate change have joined calls for a global moratorium on new coalmines.

Leaders from the Cook Islands, Kiribati, Marshall Islands, Nauru, Palau and Tuvalu demanded the world limit the global temperature rise to 1.5 degrees Celsius and that countries uphold the principle of polluter pays.

At risk: The Cook Islands. Credit:Cook Islands Tourism

The declaration on climate change came ahead of a broader 16-nation Pacific Island Forum leaders summit and retreat which includes Australia and New Zealand later this week.

It follows a letter from Anote Tong, the president of the Republic of Kiribati, to world leaders last month calling for a stop to the development of all new coalmines. President Tong said that this was "an essential initial step on our collective global action against climate change" and necessary for countries like his that face "a very uncertain future".