Bougainville has voted by a landslide for independence from Papua New Guinea, according to official referendum results released Wednesday, a major step toward creating the world’s newest nation.

Bertie Ahern, chairman of the Bougainville Referendum Commission, said 176,928 people — 98 percent of voters — had backed independence, with just 3,043 supporting the option of remaining part of Papua New Guinea with more autonomy.

The result of the referendum must be ratified by Papua New Guinea’s parliament — where there is some opposition to the move — but the scale of the victory for the pro-independence side will heap pressure on Port Moresby to recognize the result.

Speaking in Buka, Ahern urged all sides to recognize the result and said the vote was about “your peace, your history, and your future” and showed “the power of the pen over weapons.”

The historic vote caps a decadeslong peace process and a long recovery from a brutal civil war between Bougainville rebels, Papua New Guinea security forces and foreign mercenaries that ended in 1998 and left up to 20,000 people dead — 10 percent of the population.

“The referendum is one part of that ongoing journey,” said Ahern.

The former Irish prime minister was picked for the role having shepherded the Northern Ireland peace process.

Voting began Nov. 23 with ecstatic residents — some festooned in grass garlands — forming makeshift choirs that stomped through the streets, waving independence flags, blowing bamboo pipes and chanting in chorus.

The result will encourage mining interests that want to reopen the massive Panguna copper resource. At the junction of the Pacific and Southeast Asia, and halfway between Brisbane and the U.S. military base on Guam, Bougainville has a strategic interest as well as being a potential source of contracts for mining and construction companies.

With fewer people than Pittsburgh, an estimated per-capita GDP of about $1,100 and an economy reliant on money from the central government, Western diplomats are concerned that if it becomes independent it may be susceptible to China’s increasing influence in the region.

PNG Prime Minister James Marape also will be nervous that the result will embolden independence claims in some of the nation’s other provinces, which would undermine the government’s efforts to unify a country that has more than 800 languages and was constructed from a colonial carve-up less than 50 years ago.

Bougainville’s massive copper deposit has been the country’s blessing and curse. The Panguna mine was the focal point of a 10-year civil war and has been shut since 1989, shortly after the conflict started, tainted by its bloody past and fettered by a tangle of environmental and ownership issues. But it remains central to what will happen to the islands.

The old Panguna mine has an estimated 5.3 million metric tons of copper and 19.3 million ounces of gold, according to former operator Bougainville Copper Ltd. That would make the reserves worth about $60 billion at today’s prices.

“In many ways the referendum is the easy part,” wrote Gordon Peake, a visitor at the Australian National University who has studied Papua New Guinea for 15 years, in a WhatsApp message from the venue in Buka. “The vote is non-binding and the peace agreement says the parties must now consult on the result, with PNG having final decision. This phase likely to be long and involved.”