This is having a "very significant" impact on KiwiRail he said, though he was unable to put a dollar value on the disruption as the costs were still being quantified.
Miller was speaking at the Transport Select Committee this morning and told MPs that the virus was hurting KiwiRail.
Speaking to media after the committee hearing, Miller said he has had to put some train drivers to work in other areas.
"We're putting people on leave; we're doing everything that the forestry sector is also doing [in order to] stay alive for the rebound."
So far, KiwiRail has not asked the Government for additional funding to help cover its costs, he said.
But asked if he planned to, Miller said he was not yet sure.
"We need to see how long this lasts – if it rebounds in the next few weeks, we probably don't need to.
"But if it goes longer than that, we probably will need to have those discussions."
He wouldn't say how much KiwiRail would be asking for.
But he is expecting a rebound soon.
"There are signs that the China market is starting to talk again about the import volume and the frequency," he said.
"It just might take a little bit longer than anticipated."
The Government has already earmarked $11 million for the tourism sector, which has taken a sizable hit due to the decreased number of Chinese tourists.
At her post-cabinet press conference this week, Prime Minister Jacinda Ardern said the Government was looking at a relief package for the forestry sector as well.
"Now at ports we are almost getting to capacity in receiving logs, so we're looking at potential initiatives for the logging sector."
She said the Government would be providing some "flexibility" for effected logging companies when it comes to tax.
