Kiwirail is promising freight train services in Northland suspended as a result of the discovery of asbestos in locomotives will be restored as soon as possible.
The company has taken its new Chinese-built locomotives off the rails after finding asbestos under paint, inside door panels and in roof cavities.
As a consequence, it had to rationalise freight services in the South Island and central North Island.
Northland is the only region in the country where no trains are running.
Rail freight in the region has been under review for some time because of low volumes, and there has been speculation that Kiwirail has made an early decision to cease operations in the north.
Kiwirail freight operations manager Aaron Temperton said that was not the case.
The company had had to call all its older locomotives into service in areas of high demand while the new engines are off the rails, he said, and KiwiRail was able to suspend the Northland service with the least inconvenience to customers
Mr Temperton said freight volumes in Northland are low, and logs and milk powder can be stockpiled for a period or trucked.
Kiwirail is consulting experts, unions, Worksafe and the Chinese manufacturers on how to remove the asbestos from its new locomotive fleet.
Mr Temperton said as locomotives are made safe they will be returned to service. It will take months to put them all back on the rails but Northland is a top priority to have freight services restored. This would happen in a matter of weeks, he hoped.
Kiwirail said the suspension of rail-freight in the north has led to an increase of about 20 trucks a day on the region's roads.