The New Caledonia government said a large cyber attack launched soon after the announcement of Macron's visit had aimed to make internet services unavailable, with millions of emails sent to one address.

The attack had been stopped and its origin was unknown, an official said in a live-streamed press conference on Wednesday.

"The different emails that were launched came from several countries at the same time," the official said.

"They wanted to clog the New Caledonia cable."

France's High Commission said Macron would be accompanied by ministers for defence and interior for Thursday's talks, and some 100 members of the GIGN or elite tactical response group were deployed in New Caledonia.

More than 1000 security reinforcements from France were on the ground, some 90 barricades had been cleared from roads, and the night had been calmer despite two fires in Noumea, the high commission said on Wednesday.

Some 20 arrests were made on Tuesday, with 280 rioters arrested in the past week.

Jimmy Naouna, from the Front de Liberation Nationale Kanak et Socialiste (FLNKS) of New Caledonia, said the pro-independence political party had called for protesters to remove roadblocks, which are restricting movement and supply of food in the capital Noumea, yet they continue to appear overnight.

"The police forces go around clearing these barricades but the youth right after that, they put them up again, so it's almost a cat and mouse game," he told Reuters in an interview.

"We will see what happens when Macron gets here."

Noumea Mayor Sonia Lagarde, a member of Macron's Renaissance party, said she hoped Macron's visit would help "cool things down" and that he would announce a postponement of a joint session of France's National Assembly and Senate to ratify the electoral reform passed by the lower house.

"I am worried about my city, which is widely destroyed notably in the northern district ... Noumea today is a martyr city, a city under siege," she told France 2 TV.

FLNKS, the party of the New Caledonia government's president Louis Mapou, wants Paris to scrap an electoral reform.

"We are expecting if he travels to Kanaky he will make some strong announcement that he is withdrawing this electoral bill, but if he is just coming here as a provocation that might just turn bad," Naouna said, using the island's indigenous name.

The protester organiser, Field Action Co-ordination Cell (CCAT), called on social media for protesters to display Kanak flags and banners opposing the electoral amendment.

"We don't know what Macron and his team are coming to do but we remain mobilised and confident for Kanaky," it said.

Macron will meet elected officials and local representatives on Thursday for a day of talks focused on politics and on the reconstruction of the island, his aides said.

France annexed New Caledonia in 1853 and gave the colony the status of overseas territory in 1946.

New Caledonia is the world's third-biggest nickel miner but the sector is in crisis and one-in-five residents live below the poverty threshold.

The island is more than 16,000km from mainland France and some 1500km east of Australia.

More than 100 foreign tourists were evacuated on Australian and New Zealand government-chartered flights on Tuesday, as New Caledonia's airport remained closed to commercial flights.

The US State Department said one US citizen was among those evacuated to Brisbane.

Minister for the Pacific Pat Conroy said the French government was organising Wednesday's evacuation flights to Australia.

Australian diplomats were "working very hard to make sure as many Australians as possible are on those flights", he said.

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