The magnitude-7.8 quake that struck New Zealand's South Island left two people dead and triggered a small tsunami. It also brought down rocks and mud that swept across highways and cracked apart roads.
The defense force said it had started ferrying people out by military helicopter and that a navy ship from Auckland was due to arrive in the area Wednesday morning.
Home to about 2,000 residents, Kaikoura is a popular destination for travelers taking part in whale-watching expeditions or wanting a stopover with mountain views. But the quake knocked out water supplies and sewer systems and left people with no easy way out.
"From all directions, Kaikoura has essentially been isolated," Air Commodore Darryn Webb, acting commander of New Zealand's Joint Forces, told The Associated Press. "There's a real imperative to support the town because it can't support itself."
Webb said the military was using four NH90 helicopters that could each transport about 18 people at a time out of the town. He said the navy ship could pick up hundreds of people if weather conditions allowed.
"We're going to get as many people and belongings out as quickly as we can," Webb said.
He said the operation could take several days.
Air Force Wing Commander Scott McKenzie said in a statement that military personnel were delivering food, water, diesel fuel and other basic necessities by helicopter. Authorities have prepared about 5 metric tons (5.5 tons) of supplies in the city of Christchurch.
Sarah Stuart-Black, director of the Ministry of Civil Defence and Emergency Management, said the priority was transporting out those people with health issues or bookings on international flights.
She said the community was rallying to help the tourists.
"It's fantastic that some of the locals in Kaikoura have taken in tourists into their own homes," she said.