Northland's Northport will be linked up to the main rail network as part of the government's rejigged transport upgrade programme.
The decision to invest in rail comes at the expense of the building of a new state highway, with State Highway 1 being upgraded instead, and the new rail link built to connect Northport to the North Auckland rail line.
At present, export goods from Whangārei and north have to travel to the port by road or if they are destined for ports to the south, they have to use a combination of road and rail.
Northport chair Murray Jagger welcomed the investment but said the port needed road investment as well to establish a resilient supply chain.
"It's not an either/or I don't think, we need to focus on road, rail and coastal shipping. So it's one of the jigsaw puzzle pieces," Jagger said.
"The road is a crucial part of infrastructure to allow the region to grow and prosper so that shouldn't be ignored."
Northport had previously been floated as an option for relocating Auckland's port operations, although no decisions have been made on its future as yet. Rail had been seen as key to making such a proposal work.
Jagger viewed the rail investment as supporting a better supply chain overall, rather than helping the port to replace Auckland.
"We will play a very important part of supply chain delivery in the future and that includes road and rail but it doesn't exclude Auckland either.
"We were seeing just recently with the global freight challenges that Auckland is still a very integral part of that upper North Island resilience story and this is not about removing the requirement for Auckland to stay where it is, it is actually adding any more value into a system with the challenges that they have."