Excited voters gathered in Buka to hear the results — and they cheered when the sheer scale of the victory became apparent.

The nearly unanimous results exceeded what regional analysts had expected and could accelerate the independence movement, complicating diplomatic relations across the region.

“Like many Bougainvilleans, I am relieved that the referendum has concluded, that we have honoured the memories of those lost to the conflict, and that we can now move forward in negotiating a lasting political settlement,” said Joseph Nobetau.

With such a resounding vote for self-determination, Bougainville has become a visible inspiration for other independence movements in the Pacific, from West Papua, which is seeking to secede from Indonesia, to New Caledonia, which will hold a referendum next year about possibly breaking away from France.

For Bougainville — an area with huge mineral wealth and 250,000 people — the vote also makes it much harder for PNG to move slowly through the consultation period required under the 2001 peace agreement that provided a pathway to independence.

“It puts the PNG government in a pretty hard position,” said Jonathan Pryke, director of the Pacific Islands program at the Lowy Institute in Sydney.

“If there were to be a smaller majority, say 55 or 65%, the PNG government could have found a way to justify really stretching this out and having a period of negotiation that could last years or decades.

“Now with such a phenomenal majority, it’s much harder for them to do that,” he added.

Countries like Australia and New Zealand will also now find themselves squeezed — likely facing pleas for assistance from Bougainville to develop its institutions, and resistance from PNG, which has never been eager to give up Bougainville’s bounty.

The islands have struggled against PNG’s rule since the 1970s. At the time, Bougainville’s Panguna mine provided nearly half the entire country’s export income through gold and copper mining. But little tax revenue seemed to make it back to Bougainville.

Its economic grievances led the region to declare independence, or try to, in 1975. But Papua New Guinea ignored that push, and over the ensuing decades, tensions simmered then exploded. Violence shut down the mine in 1989 and a nine-year war claimed the lives of 20,000 people.

The Bougainville Peace Agreement granted the region more autonomy, and those who opposed secession hoped the pact’s lengthy timeline — allowing for a nonbinding referendum on independence within 20 years — would also prompt PNG’s government to develop an equitable revenue-sharing deal for the mine, along with other services that might build loyalty to the central government.

But that never happened.

“The PNG government has squandered its opportunity,” said Wesley Morgan, a fellow at Griffith University’s Asia Institute in Queensland, Australia.

Now, Bougainville has the potential to become the world’s newest nation, defining its own destiny and opening itself up to diplomatic and economic partnerships with nations that have shown increased interest in the Pacific as of late — including the United States and China.