Mr Key also said he was considering "throwing some money" at an worldwide online campaign to promote Kaikoura once road access had been restored to reassure tourists it was safe to visit as the peak summer season approached.
A convoy of 27 military trucks reached the stricken New Zealand town of Kaikoura on Friday, five days after the seaside community was completely cut off by huge landslides caused by a 7.8-magnitude quake that killed two people.
"They could assist in the clean-up, movement of vital aid supplies and in conducting welfare checks in communities affected by Monday's quake".
China sent four helicopters to airlift 40 Chinese tourists from the area.
"Evacuations will continue for as long as necessary and, as of tomorrow, several ships from other nations - including the (U.S. Navy destroyer) USS Sampson - will arrive off the Kaikoura coast ready to be mobilized as required".
The NZDF forces at Kaikoura would be joined over the next day by Australian, Canadian and USA warships with their embarked helicopters.
With damage expected to take months to fix, the government announced a NZ$7.5 million (RM23.06 million) package to support small businesses in Kaikoura for two months. In February 2011, a magnitude 6.3 natural disaster struck the same area.
Many buildings in the capital have been sealed off amid fears they have sustained structural damage, including an office block housing the defence department's headquarters.
The government said on Thursday it would investigate why the newer buildings had been unable to withstand the quake.
"It is a concern, people do want to know the buildings they're in are going to be safe", Wellington Mayor Justin Lester told reporters. "There's no simple answer".
Flood water flows through cracks in the road surface on Udy Street, Petone, after a bout of severe weather on November 15, 2016 in Wellington, New Zealand.
Civil Defence evacuated some residents near the Hapuku and Ure Rivers, further north, where landslides from the earthquakes had blocked the rivers.
Storms lashed the region on Thursday and seismologists were still recording hundreds of aftershocks - some 2,000 have rattled the region since the initial tremor shortly after midnight on Sunday.
Government body Geonet Science estimated an nearly one-in-three chance of another 7-7.8 magnitude quake hitting the region within the next 30 days.
"We stress to Wellington that we need to be prepared", Wellington Mayor Justin Lester said.