Road access will be restored to quake-hit Kaikoura within days, Transport Minister Simon Bridges says.
But repairing State Highway 1 and the rail lines either side of the South Island township will take months and is likely to cost hundreds of millions, he said.
The tourist town near the epicentre of the Magnitude 7.5 quake has been cut off by landlips and people trapped in the town are gradually being airlifted out.
Speaking to reporters at Parliament this afternoon, Bridges said he had planned to fly into the region today to inspect the damage from yesterday morning's quake but was thwarted by poor weather.
He said the New Zealand Transport Agency was working around the clock to fix bridges on a local, inland road - previously known as State Highway 70 - into Kaikoura.
"What I can say, for the people of Kaikoura, is that we are talking about days not months, and they are working as fast as they can."
State Highway 7 has already been reopened to allow freight to get to and from the Canterbury region. And Highway 7a to Hanmer Springs is also open, though there is a curfew in the evenings because of debris and landslips.
Bridges said the next priority was to rebuild State Highway One and the coastal railway. While some realignment was likely, Bridges said it would still be a coastal route.
The highway between Seddon and Cheviot was "in an incredibly bad way" with several slips and roads which had been shifted by the quake.
"In that instance, we are clearing talking about several months to get that into position."
Bridges said it was not just a quick fix, but a long-term rebuild which meant the transport routes were not vulnerable to future earthquakes.
Seven bridges on the road and rail line needed major repairs, and 14km of the route had been affected by the massive tremor.
Speaking about the potential clean-up cost, Bridges said a major slip in the Manawatu Gorge im 2011 cost $35m to clean up, and there were at least seven major slips on SH1.
The NZTA had $500m for state highway repairs and another $200m to $300m for emergency repairs. If the cost of repairs exceeded that amount, the Crown would cover it.
Kiwirail might also need a funding boost for the rail line to re-open, Bridges said.
"If that's what's necessary. Let me be very, very clear - we are going to get State Highway One back up and running. We are going to get that rail line back up and running."