A former prime minister of Vanuatu says the Melanesian Spearhead Group is becoming ineffective because of games being played by Fiji and Papua New Guinea.
A leader's summit for the regional group originally scheduled for this week has again been postponed without explanation.
This comes as the MSG grapples with a bid for full membership by the United Liberation Movement for West Papua, which is opposed by Indonesia.
Barak Sope, a staunch advocate for West Papuan independence, said the group has become ineffective because Fiji and Papua New Guinea, which both support Indonesia, are dodging making a decision.
"My view is that it's just a game between the government of Papua New Guinea and the government of Fiji," he said.
"I think they're working with the Indonesians, and they're not supporting the Melanesian people in West Papua who want their independence. The postponements just keep on going on."
Mr Sope said the three remaining members of the MSG - Vanuatu, Solomon Islands and New Caledonia's FLNKS - should go ahead and make a decision without the other two.