The Polynesian Leaders Group, meeting today in Auckland, is planning to focus on the enforcement of fisheries management in the Pacific.
The group, set up five years ago in response to a resurgence in the Melanesian Spearhead Group, includes the leaders of eight Polynesian states and territories.
They meet each year but to date there has been little other activity by the leaders.
It will be the first foray into foreign affairs by Tonga's new prime minister, Akilisi Pohiva.
The current chair of the group, Niue's Toke Talagi, is due to hand over to the Samoan Prime Minister, Tuilaepa Sailele Malielegaoi.