The future independence of Bougainville from Papua New Guinea statehood has thrown up a fresh dilemma over the sovereignty of a neighbouring island nation.

The Premier of the most northern Solomon Islands province to Bougainville has declared Choiseul intends to join PNG's autonomous region when it becomes a fully-fledged nation in 2027.

While Port Moresby has begrudgingly but willingly accepted the province's move to independence after a prolonged period of conflict and negotiation, Honiara is expected to hold discomfort towards letting go of Choiseul.

Like most islands which form the Solomon Islands, Choiseul historically shares cultural ties with Bougainville.

Bougainville was once a part of the Republic of the Northern Solomon Islands that existed in 1975 and 1976 for around six months, along with Choiseul and other current islands of the Solomon Islands: Santa Isabel, the largest of the three islands that make up the Isabel Province, and the Shortland Islands ward of Western Province.

But soon after Papua New Guinea gained its own independence from the Australian administrative control of the time, the North Solomons ceased to exist, while Bougainville were forced to unify with a new Papuan cultural nation.

Choiseul premier Harrison Pitakaka sounded the alarm of his province's latest intention to leave the Solomon Islands in their own act of independence and unification.

His pro-Bougainville switch stems from remarks on an online news thread following Choiseul's provincial opposition's visit to the Solomons' Western Province on Tuesday.

The Opposition leader Matthew Wale was conducting dialogue with key Western Province stakeholders over major national project sites for the good of the Solomon Islands.

"We took the responsibility to be here to hear first-hand the challenges faced by Western Province," he said, "and how we can better advocate for the province at the national level".

But Premier Pitakaka rebuked the visit by peculiarly describing the comments as "unfair".

Mr Pitakaka said some provinces are contributing to a national basket which benefited other provinces and not those that contributed the projects.

It was reported across the online forum that he said Temotu and Choiseul provinces will be fast-tracking a unified quest for national cessation.

The premier added he had already started consulting last year with his Temotu provincial counterpart over a joint cessation.

"We are working on that line," Mr Pitakaka said online.

"Much has been felt about it with my people.

"It takes the right time to pull the trigger."

Mr Pitakaka has also only been leading the province since last year.

The move of political expediency could come down to a review of the provincial government's assembly, he said.

"We need to explore something else."

While Bougainville's push towards nationhood has been buoyed by Papua New Guinea's newest commitment to stay out of the province.

The PNG Defence Force once fought a bloody civil war against Bougainville rebels for several years, largely over a productive copper mine, before the country's police force later patrolled the streets in high numbers to regain control.

"We will put it into law in our constitution: never again will the PNG Defence Force set foot on Bougainville; never again will our police step on Bougainville," Prime Minister James Marape said.

"The scars are too big.

"I don't want those scars to re-open again."

Marape warded off all attempts to get him to make a commitment on behalf of the government on a date for ratification of the 2019 referendum, where 97 per cent of Bougainville residents were in favour of outright independence from Papua New Guinea.

"Parliament has not been provided with an opportunity to deal with the report," he said over why the parliament had not ratified the report.

The referendum report remains with PNG's executive government, which was going through the process of negotiation with the Autonomous Bougainville Government.

Marape said that all administrative powers, including those in control of the economy, had now been devolved to the autonomous government and the future was in Bougainville's hands.

He would not be drawn into making any commitment on the September 2027 deadline, set by Bougainville's leaders for a decision on its independence.