France's president made a long-haul trip to the restive Pacific territory of New Caledonia on Thursday, urging a "return to peace" after deadly rioting, and vowing thousands of military reinforcements will be deployed for "as long as necessary".

Emmanuel Macron arrived in the capital Noumea after a 24-hour flight seeking ways to end more than a week of looting, arson and clashes that have left six people dead and hundreds injured.

As he exited the plane at Tontouta International Airport, the French leader told reporters he wanted to ensure that "as quickly as possible there will be a return to peace, calm, security".

"That is the absolute priority," Macron added, as he prepared to launch a day of intensive meetings with local leaders.

Later, he described the unrest as an "absolutely unprecedented insurrection movement".

"No-one saw it coming with such a level of organisation and violence," he said while visiting a police station in the capital Noumea.

Praising security forces for "professionalism" and "cool-headedness", he vowed Paris would "go until the end" to quell the worst violence to erupt in the territory in four decades, warning that "the coming days and weeks will still be difficult".

He is expected to spend about 12 hours on the ground.

France has ruled New Caledonia since the 1800s, but many Indigenous Kanaks still resent Paris' power over their islands and want fuller autonomy or independence.

Since May 13, separatists have cut off whole neighbourhoods and the main route to the international airport, which remains shuttered.

Nightly riots have seen scores of cars, schools, shops and businesses burned.

French authorities have imposed a state of emergency, placed separatist leaders under house arrest, banned alcohol sales and sent around 3,000 troops, police and other security reinforcements to quell the turmoil. (AFP)