The United Liberation Movement for West Papua says it is vital that West Papuans have full membership in the Melanesian Spearhead Group.
The ULM was formed late last year at a major summit of West Papuan representative groups hosted by the Vanuatu government.
Representatives of the ULM have returned to the Vanuatu capital to formally submit the organisation's application for membership of the MSG.
A member of the movement, Rex Rumakiek, says the time is right for West Papua to join the sub regional group.
"Economically and for security reasons, it is vital that West Papua must be part of the MSG. We have elaborated on security matters and the spread of terrorism and economic expansion an all those things. It is justified that it is important that West Papua must be part of the MSG."
Rex Rumakiek says MSG leaders do not need the endorsement of Indonesia's government to accept the membership application.
MSG leaders are due to have their annual summit in June, in Honiara.