Finance minister Nicola Willis told reporters on Thursday that officials had discussed using legislation introduced to restrict fuel use in the wake of the Iranian revolution in 1979 in response to the crisis.

Under those laws, car owners had to nominate one day per week when they would not use their vehicle and faced hefty fines if caught driving.

They also allowed the government to authorise the sale of coupons to restrict fuel use, and restrict the amount that could be sold.

The so-called "carless days" were in effect from July 1979 to May 1980.

The minister's comments came as oil prices surged back above $100 a barrel on Thursday.

Iranian attacks on shipping have effectively closed the Strait of Hormuz in response to the US-Israeli strikes that killed Supreme Leader Ayatollah Ali Khamenei.

In New Zealand, which is heavily dependent on imports for its fuel, the average petrol price has increased by nearly 10 percent since the war began, with diesel up more than 20 percent, according to price monitor Gaspy.

Willis said the car restrictions would only be needed "if we were seeing genuine disruption to our ability to get fuel".

Energy minister Shane Jones said there was about 50 days worth of fuel in or on route to New Zealand.

National airline Air New Zealand also announced Thursday it had cancelled five percent of its flights for the next two months, mainly on domestic routes, due to increasing jet fuel costs.

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Air New Zealand