The United Liberation Movement for West Papua says it's not interested in one-on-one dialogue with Indonesia's government.
Various Papuan civil society, church and customary leaders met with Indonesia's president Joko Widodo last month about establishing dialogue over problems in Papua.
The Jakarta meeting agreed on the Catholic priest, Neles Tebay taking on a mediator role.
However so far the Liberation Movement has not been included in the dialogue process.
Its secretary-general Octo Mote said Jakarta's offer of dialogue appeared to be timed for good publicity ahead of meetings of the Pacific Islands Forum leaders and the UN General Assembly.
"It's too late. The world knows that we tried for the negotiations with Indonesia for years. We are only interested when internationally-mediated negotiation (happens), not dialogue. Internationally-mediated negotiation."
Terms of reference for the dialogue have not been confirmed yet, but those at last month's meeting indicated President Widodo wanted to advance talks about economic and social development in Papua.
Jakarta overture to Papua questioned
Although the Papuans at the Jakarta meeting had been pressing for dialogue on issues of human rights abuses in Papua among other problems, the term "sectoral" has been used to describe the matters up for discussion.
According to Mr Mote, it is unclear what the Indonesian goal of dialogue about "sectoral" matters refers to.
He said the Liberation Movement's mandate as a representative body for West Papuans was to campaign for independence, and that this would not change.
"We don't pay attention to any dialogue (between Jakarta and Papuans). Our focus is getting the members of the countries at the UN to put West Papua back on the UN agenda," Mr Mote explained.
"So if Indonesian government wants to do dialogue about development issues, just go ahead. They can do it."
The Liberation Movement is recognised by the Melanesian Spearhead Group which is an international collective whose full members are Papua New Guinea, Solomon Islands, Fiji and Vanuatu and New Caledonia's FLNKS Kanaks movement.
Mr Mote said that in accepting the Liberation Movement and granting it observer status, the MSG had taken up a role as a vehicle for the West Papua self-determination and human rights issues to be addressed at the international level.
"So they created a forum where this kind of communication can be taking place," he said.
However, according to Mr Mote, Indonesia has rebuffed efforts by the MSG chairman Manasseh Sogavare of Solomon Islands to confront the Papuans' core grievances.
"That means Indonesia closed this kind of communication," said the Liberation Movement secretary-general who is currently in Samoa to attend the Pacific Islands Forum annual summit.
The government of Indonesia, which has associate member status in the MSG, said it was working hard to improve living conditions in Papua region through economic development.
Indonesia said the incorporation of Papua into the republic was final, and its security forces take a firm line in disallowing expressions of Papuan independence aspirations.