Oil companies operating in New Zealand said on Friday they were willing to work with the government, to ensure the country boosted its oil stocks to meet international obligations.
On Thursday, Energy Minister Pete Hodgson said a review of reserves had shown New Zealand had the equivalent of only 60 days of stocks, below the minimum required by the International Energy Agency of 90 days of net imports.
BP managing director Peter Griffiths said BP would co-operate with government agencies as they explored possible ways to do meet IEA obligations.
According to BP, the reserve shortfall was in the order of 400,000 tonnes, representing some NZ$200 million ($132 million) in product costs alone.
"Given the growth in New Zealand's energy demand and the decline in indigenous production, the reduction in holdings should not be too much of a surprise," Mr Griffiths said in a statement.
According to BP, domestic oil production, which accounts for about 20 percent, had fallen by 60 percent since 1997.
The issue had nothing to do with being able to meet New Zealand's day-to-day fuel requirements and there was no risk of any supply disruptions, he said.
Shell New Zealand Ltd spokesman Simon King said his company was happy to work with the industry and the government to ensure the IEA requirements were met.
However, there were issues with storage capacity, he said. "If we did need extra supply, that means extra cost."
Hodgson said on Thursday the government was consulting with oil companies on the best way to increase stocks to the required minimum level. Legislation already existed to pass regulations requiring oil companies to maintain 90 days of reserves.
New Zealand's oil industry is dominated by four major companies - BP, Mobil Oil New Zealand, Caltex New Zealand and Shell New Zealand.
The country consumed around 5.6 million tonnes of oil products, mainly petrol and diesel fuel, in the year to September 2003, according to official data.