A port pile-up that will restrict movement in and out of New Zealand of essential goods is looming fast if the Government doesn't recognise that all freight must move in the State of National Emergency, says Road Transport Forum chief executive Nick Leggett.

"Truck drivers are providing an essential service. If the Government wants essential goods to have freedom of movement at this critical time, they cannot tinker with freight definitions.

"This is going to cause massive problems in the next month that will restrict the movement of food and medical supplies that come into ports around New Zealand.

"Our industry totally supports the move to a State of National Emergency to prevent the spread of COVID-19. We know this is a very serious situation."

Nick says closing down the country to the scale we have now hasn't been done before and it does reveal some issues that need to be addressed pragmatically.

"We have been working with government officials who have been logging incredible hours and are committed to solving problems. However, they take their orders from the top and like the rest of us during this time, must do what they are told.

"To explain this situation, ships arrive at ports in New Zealand and are unloaded. All manner of freight can be on one ship and even within one container. To make way for the cargo to go on that ship so it can leave, and for all the other cargo coming in at the same time, freight needs to be constantly moved off the ports. Truck drivers do that.

"We now have a situation where many businesses that receive some of that freight are closed and there is nowhere for it to go. If it is deemed by the Government to not be essential, it cannot be moved. Even by the end of this week, some ports will be struggling. If containers aren't unloaded there will be a shortage of containers for goods going out."

Nick says the Government needs to understand that all freight needs to move during this time to enable the valuable exports that are going out, such as kiwifruit, access to ports.

He says ships will stop coming if they cannot unload, and New Zealand may miss out on essential supplies.

"Shipping from Asia has picked up again and in Auckland for example, they are expected 14,000 cars to be shipped in over the next month. Those cars cannot stay on the port; they have to go somewhere. The dealers that would normally take them are closed.

"We appreciate cars are not an essential service, however, they are holding space that is needed for essential goods.

"Our industry is looking at how we could find storage for the freight with nowhere to go, but we need the Government to allow that freight to move.

"We are trying to work with Government throughout this pandemic to ensure road freight has the support required so that people don't have to stress about having vital supplies as they go into lockdown."