Transport Minister Michael Wood warns that supply chain problems at the ports will continue for much of this year.
Wood told the Transport Select Committee that the global index of shipping reliability is at the lowest levels ever recorded.
He says Covid-19, industrial action at port in Australia and extreme weather events have all impacted reliability.
"We're dealing with a global problem, it is not something that we can fix and unfortunately we expect it to last well into this year," he said.
Wood said domestically there were also problems with cranes and staffing at Auckland Port, which was creating the "perfect storm".
"There are questions there for Ports of Auckland around that, but we've got to be practical and work with them as much as possible to try and mitigate the impact, which is what we've been doing," he said.
The ministry had been working to bring the supply chain sector together to come up with solutions, he said.
"We've been working with KiwiRail to put on additional services, to move freight around more quickly," he said.
Ministry of Transport chief executive Peter Mersi said all of the parties in the freight industry had been leaning in to help make the system work.
"I know in the lead up to Christmas and over Christmas there were concerns about medicines that were on vessels and concerns that we might not be able to get them off in time to maintain the supply in New Zealand.
"With the help of the ports, the identification by the freight forwarders of specific containers, they were actually able to bring specific ships in, unload those containers and then allow the rest of the system to go back to normal," he said.
Everyone was doing what they could to reduce the impact, he said.
An all-sector meeting is being held next week to look at possible solutions, after the meeting was delayed due to the latest Covid-19 outbreak.