France will be cut out of regional leaders' final discussions on New Caledonia at the upcoming Pacific Islands Forum Leaders Meeting.
The situation in crisis-hit New Caledonia will top the agenda when leaders, including Australia's Anthony Albanese and New Zealand's Chris Luxon, gather in Tonga next week for the Forum's annual summit.
Noumea has been the scene of deadly riots in recent months after a rebellion by the pro-independence Kanak population against voting reforms planned by France.
A political resolution is yet to be reached, though order has been largely restored through Emmanuel Macron's government sending in hundreds of French police.
The dispute is essentially one between the indigenous Kanak population and France as the colonial power, and both will be represented in Tonga.
Louis Mapou, the New Caledonia president, and Veronique Roger-Lacan, France's Ambassador to the Pacific, will be putting their case to regional neighbours at the meeting.
However, only Mapou, representing the Melanesian nation, will be present for the climax of talks: the closed-doors all-day leaders retreat, being held on the outer island of Vava'u next Thursday.
The leaders retreat is the centrepiece of each annual meeting and a form of regional diplomacy unique to the Pacific.
Only the 18 PIF leaders - with one note-taker each - are allowed to attend the retreat, which makes all decisions by consensus, meaning each nation - from tiny Pacific islands to regional powerhouses - get a similar say.
France is not a PIF member and will not be represented around the table.
New Zealand's Deputy Prime Minister Winston Peters said the leaders retreat was "most definitely" the appropriate forum to thrash it out.
"It won't antagonise the French because we have been having these meetings ever since (the forum was founded) in 1971," he told AAP.
Pacific leaders had hoped to benefit from a fact-finding mission to Noumea, but the trip was cancelled due to a spat between Noumea and Paris over the terms of the trip.
That private dispute has been coupled with a very public war of words.
The President of the New Caledonian parliament, Roch Wamytan, this week said France was "demeaning" the forum with its demands.
Speaking to Radio NZ, Ms Roger-Lacan responded with a firm statement of sovereignty.
While saying Paris "totally recognises" the UN-backed decolonisation process, until it is achieved, France was its "administering power".
"New Caledonia is France and it's legally in international public law ... that is how it is," she told Radio NZ.
In a speech last month, Mr Peters went further than any other western diplomat towards blaming France for the unrest, suggesting the voting reforms did not follow the spirit of the Noumea Accord, the country's independence pathway.
Mr Peters - who insisted it was a balanced speech, also sympathetic to France - said he had "a lot of comments" in support of his address.
"I'm not saying who - but they did appreciate our independent, mutual, balanced and logical way we set out the case for a reconciliation," he said.
The veteran Kiwi diplomat cautioned against expecting a resolution to emerge from Tonga.
"Contributing positively to a sustainable long-term situation and solution: that is our purpose," he said.
"We want there to be one voice from the Pacific in a helpful way to both New Caledonia and France."
A mini-summit may be held en route to Nuku'alofa on Saturday.
New Zealand will take six Pacific leaders to Tonga, along with the UN Secretary General Antonio Guterres, on the same NZDF flight from Auckland.
Those on board include Samoan Prime Minister Fiame Naomi Mataafa and Vanuatu President Charlot Salwai.
