The Solomon Islands Government says it will not back the United Liberation Movement for West Papua as a full member of the Melanesian Spearhead Group.
The Manasseh Sogavare-led government, which hosts the MSG Leaders summit next week, says it will endorse West Papua to be an observer and this status would be "given only to one united group".
In a statement, the Government says it would agree that any submission for full membership by a group representing Melanesians throughout Indonesia must be united and done in consultation with Indonesia.
It says it also wants the MSG to continue looking at ways to make Indonesia an associate member of the MSG.
The Government says it has made its decisions to enhance Melanesian solidarity, values, continuity and maintain good neighbourliness.
The New Caledonia FLNKS and Vanuatu have traditionally backed West Papua's push to join the MSG, but Port Vila's position is unclear after the toppling of the Natuman Government.
Fiji has been strongly backing the Jakarta position and the leadership in Papua New Guinea has been ambivalent on the issue.
A Solomon Islands MP has labelled as vague and weak the government's official announcement on the West Papuan bid to join the MSG.
Mr Sogavare hasn't specified if his administration backs the United Liberation Movement for West Papua for gaining observer status.
It says it also wants the MSG to look at increasing Indonesia's representation in the MSG.
To the West Makira MP, Derrick Manuari, the announcement is a sign of weak decision-making, given the strong public support for the West Papuans
"The decision by the government of Solomon Islands is not good enough. It misrepresents the public opinion of Solomon Islanders and the very people whom they represent in government. The government is actually using rhetoric to continue their vagueness on the position on the West Papua issue."
Meanwhile, media in Indonesia is reporting that a petition organised by the West Papua National Committee to voice support for the ULMWP's application to join the MSG has been signed by 157,427 people.
Support among the indigenous people of Papua region for the West Papuan MSG bid is huge, according to a Dutch journalist working undercover in the region.
Rohan Radheya says recently there have been many demonstrations in support of the bid.
"All the people I talk to, they are very optimistic that their Melanesian brothers and sisters will vote in their favour. They are hopeful but they're also very afraid... sort of: what next, after that, if we are abandoned again? That would be such a hard blow for them because they have worked for this MSG membership for such a long time. And if they get rejected that would definitely be a knockout blow for them."
Mr Radheya says many Papuans who demonstrate support of the MSG bid have been taken in by Indonesia's security forces.