A man raises his hands as he prepares to cast a vote in Buka, the Autonomous Region of Bougainville on Saturday. AP

Amid singing, dancing and the beat of drums, John Momis, the president of Papua New Guinea's region of Bougainville, was one of the first to cast his ballot early on Saturday in a referendum on whether to become the world's newest nation.

Voters in the island cluster at the heart of the Pacific are expected to overwhelmingly back independence, Sydney’s Lowy Institute think-tank says, at a time when Australia, China and the United States are jostling to step up regional influence.

Momis, accompanied by his wife Elizabeth and senior leaders, voted at a polling station in Bel Isi Park in the interim regional capital of Buka, while urging voters to stick to a peace process brokered between combatants two decades ago.

John Momis (C) arrives at a polling station to cast his ballot in an historical independence vote in Buka on Saturday.

“Bougainville has come a long way,” said Momis, raising his voting paper before putting it in the ballot-box. He thanked government officials in PNG and Bougainville for their resilience in arriving peacefully at the moment of the vote.

The non-binding referendum, which runs from Saturday to Dec.7, is a key part of a peace agreement reached in the aftermath of a decade-long war between Bougainville's rebel fighters and PNG forces that took about 20,000 lives.

The fighting was triggered by disputes over the now shuttered Panguna gold and copper mine, run at the time by a forerunner of giant miner Rio Tinto, set off by anger over land royalties and rivers polluted by mining.

On Saturday, people queues formed at polling stations across the South Pacific archipelago, where more than 200,000 people have registered to vote, with many people holding the region's predominantly blue flag.

Bougainville residents gather at a polling station in an historical independence vote in Buka on Saturday.

“It gives this generation of Bougainvilleans a chance to achieve the dreams and aspirations of our forefathers,” said Gerald Turumanu, from the southern village of Malabita.

The result of the referendum, which offers voters the choice of independence or more autonomy, will go before the PNG parliament in its capital, Port Moresby, and be subject to negotiation.

Ahead of the vote, chief referendum officer Mauricio Claudio said ballots from different areas would be mixed together to eliminate any risk of reprisals.

“This is to give assurance to the voters that they will not face retribution or reprisals after the polls because of how they voted,” Claudio added.

One of the poorest areas of PNG, Bougainville boasts large deposits of gold and copper that the government wants to develop to finance its independence.

Discussion over how Bougainville would sustain its independence is likely to dominate negotiations after the referendum, two PNG ministers told Reuters earlier.

Reuters