The leaders of the Melanesian Spearhead Group are expected to announce whether or not West Papua will gain full membership this afternoon.
An organisation representing West Papua independence groups, the United Liberation Movement for West Papua, was last year granted observer status within the MSG.
But Indonesia, which considers the movement a separatist group with no legitimacy, was also granted associate status.
Jakarta has this year warned Melanesian leaders to "think carefully" about any decision about West Papuan membership, and has put great effort into lobbying ahead of today's summit.
Vanuatu, a key advocate for West Papua, is pushing for the movement to gain full membership, which is supported by Solomon Islands and New Caledonia's FLNKS movement.
But Papua New Guinea and Fiji have expressed their support for Indonesia's sovereignty over West Papua, and are unlikely to support the country's removal from the MSG, which Vanuatu is pushing for.
The announcement has been brought forward to this afternoon as Fiji's prime minister, Frank Bainimarama, has to leave Honiara later today.
Church calls for consideration
The Catholic Church in Papua New Guinea said MSG leaders should consider West Papua's application.
The Archbishop of Port Moresby, Sir John Ribat, says the movement should be allowed full membership because of its representation of the indigenous Papuans, who are Melanesian.
He said human rights concerns in West Papua need to be discussed within the framework of the MSG, and Indonesia should be involved with them too, but as an observer.