Air New Zealand says around 2000 passengers a day will be hit by flight cancellations after someone digging up a kauri log damaged the only jet fuel pipeline between Northland's Marsden Point refinery and Auckland Airport.

The damage, discovered on Thursday but revealed on Sunday, happened about 8km south of the refinery and will take up to two weeks to fix.

All airlines using Auckland Airport are now restricted on how much they can refuel.

The government has committed whatever resources necessary, including sending in the Defence Force to carry out repairs, to resolve the problem with the minimum disruption, Energy and Resources Minister Judith Collins says.

A Naval vessel will be used to transport fuel around the country, while additional tanker drivers will be provided.

"Airlines have already reduced scheduled and are looking at what further changes they will need to make over the next week. But for now most flights are going ahead," Ms Collins said.

"The latest information I have is that aviation fuel supplies in Auckland remain of most concern, but that fuel supplies are sufficient for Auckland motorists."

Seven departures and seven arrivals were cancelled on Monday morning, according to the Auckland Airport's website.

Air New Zealand says it can now only take 30 per cent of its normal fuel usage. It estimates around 2000 passengers a day will be affected. Seventeen flights have been cancelled for Monday and Tuesday.

Normally direct flights from the US and Asia will stop at airports in Australia and the Pacific to refuel.

"We are doing all we can to minimise the impact on our customers, however, we also need to take all prudent steps to conserve jet fuel supplies at Auckland Airport," said the airline's Captain David Morgan.

The 170km pipeline was damaged by a digger driver hunting for swamp kauri at Ruakaka three months ago, the New Zealand Herald reports.

The pipeline remained intact but ruptured when pressure was increased on Thursday.

Refining NZ chief executive Sjoerd Post confirmed to Newshub a digger had scraped over it, and it will take 10 to 15 days to fix.

The pipeline also supplies petrol and diesel to Auckland, but motorists won't feel the impact over the next few days, Mobil Oil says.

Tankers will be able to truck petrol and diesel to the city from Marsden Point and ports, but the pipeline is Auckland Airport's sole source of jet fuel.