Ms Ardern said cargo would still be allowed entry.
“Our shelves will be stocked...there is no reason to panic buy,” she said, after the country earlier ordered indoor events with more than 100 people be cancelled.
Earlier this week, New Zealand announced one of the largest per capita stimulus packages in the world, amounting to 4 per cent of its GDP, in an attempt to soften the negative economic impact from the coronavirus outbreak.
Ms Ardern acknowledged the bans will have an impact on the economy but it was needed to stop the spread of the virus.
“If we slow down COVID-19, if we break it into small waves of cases rather than the overwhelming numbers experienced in other countries, that is how we help our jobs and economy too,” she said.