Bougainville's President Ishmael Toroama has called for the autonomous Papua New Guinea region to be given independence by 2025.
Toroama gave the message at talks between his autonomous regional government and PNG's national governments, being held in Kokopo, East New Britain.
The talks were the latest step in consultations between the two sides over how to proceed with the result of Bougainville's independence referendum, held in 2019.
In the non-binding referendum, 97.7 percent of Bougainvilleans voted for independence from PNG. However PNG's parliament must ratify the result for it to come into effect.
The national government led by James Marape has been reluctant to set a time frame for independence, saying Bougainville's self-determination is an issue to be handled carefully, as it affects all of PNG.
Toroama noted how Bougainvilleans had acted in good faith while co-operating with PNG over the last 20 years in implementing the agreement that ended a protracted civil war on Bougainville.
"When both governments signed the Bougainville Peace Agreement in August 2001 we committed ourselves to a deferred 15-year referendum period," Toroama said.
"This was to allow time to our people, on both sides, to heal the wounds of the conflict and ponder over what we need to find as a final solution for Bougainville and Papua New Guinea.
"All we have done in the last 20 years, whether in the weapons disposal or autonomy space, were intended to bring us closer to this day, when we should consult over the outcome of the referendum and reach an agreement on the future of Bougainville."
Toroama said autonomy or any future arrangement short of independence was not an option for Bougainville.
"Our position on the future political status of Bougainville is clear, and that is independence," he said.
Marape said his government remained committed to the Peace Agreement, but he reiterated concerns among PNG's leaders about the potential for the diverse country to break apart if Bougainville were to go it alone.
"Bougainvilleans and the rest of the country must come to understand that we are the most diverse country on earth, and my responsibility is to preserve the union of the country," the prime minister said.
"I assure President Toroama and the people of Bougainville that the overwhelming results of the referendum will not be diluted, and my government will respect this outcome.
"The joint consultations must find a process that clearly indicate a way forward for the people of Bougainville as well as the rest of the country."
Meanwhile, the Bougainville government delegation in East New Britain yesterday held a dawn service to commemorate Bougainville Remembrance Day.
It was on 17 May in 1990, that the late Francis Ona led a Unilateral Declaration for Bougainville's Independence, with the raising of the Flag in Arawa, Central Bougainville.
The anniversary recognises the loss of an estimated 20,000 lives in the 10-year conflict.