Leaders at the Pacific Islands Forum summit hold their plenary session in the Federated States of Micronesia, with climate change a key issue.
The Forum's annual gathering is also expected to discuss increasing the membership by two by adding two French territories on the UN decolonisation list.
Both New Caledonia and French Polynesia have been vying for years to be granted full membership, which since the organisation's inception was meant to be for independent countries only.
Fiji was readmitted to the Forum two years ago but its prime minister will not attend summits as long as Australia and New Zealand remain Forum members.
The meeting is also expected to discuss the situation in Indonesia's West Papua amid concern by Pacific Island countries over ongoing human rights abuses.
The Forum leaders are expected to discuss Papua-related items unresolved or postponed from last year's summit in Papua New Guinea.
At last year's summit, leaders resolved to request Indonesia to allow it to send a fact-finding mission to Papua.
However the Forum secretary-general Dame Meg Taylor said Jakarta has not allowed this to go ahead because the idea of a fact-finding mission is unacceptable to it.
The other two matters are the United Liberation Movement for West Papua's bid for Forum membership and its request for support for West Papua's inclusion on the United Nations Decolonisation list commonly known as the C24.
Forging more meaningful regional responses to fisheries challenges and climate change are also high on the Forum's agenda.
Smaller Pacific Island states want to explore a proposal for the Green Climate Fund, which has been set up to finance climate change adaptation and mitigation projects.
Many countries are finding access to such funds difficult, and the Forum's main metropolitan powers have been called on to take steps to help the Islanders on this front.
In fisheries, despite the greater revenues earned by members of the Parties to the Nauru Agreement, Pacific Island countries want to look at ways to benefit more from their own ocean and coastal fisheries while managing sustainable stocks.
The money Pacific countries lose to illegal, unreported and unregulated tuna fishing in the region is estimated at US$616 million, according to figures provided by the Forum Fisheries Agency.
The New Zealand Prime Minister John Key has missed the start of today's proceedings because his departure from Laos was delayed.