Australia will bolster search and rescue efforts in Christchurch, which has been devastated by a major earthquake.
It will also set up a temporary crisis centre for Australians stranded in downtown Christchurch, which bore the brunt of the 6.3 magnitude earthquake.
At least 65 people have been killed, with the death toll expected to rise as emergency workers search through the rubble for survivors.
Australian consular officials in Wellington are attempting to contact 350 Australians registered as being in Christchurch.
At this stage there are no confirmed Australian deaths.
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They are also confirming the wellbeing of an estimated 8000 Australians registered in the Canterbury region, which includes Christchurch.
Foreign Minister Kevin Rudd holds "grave fears" for those affected by the earthquake, which saw buildings "collapse like wedding cakes" into rubble.
"(New Zealand) is wonderful part of the world," he told reporters in Canberra. "Here we are at the end of our summer, there are truck loads (of Australians) there, so we are worried."
The government has sent a 73-strong search and rescue team from NSW to Christchurch, which will begin operations on the ground first thing Wednesday morning.
A second team, including medical staff, is expected to follow. Mr Rudd said "all deployable assets", including engineering and medical equipment, are also on stand-by.
"It (is) far better to throw everything at it, and if we subsequently discover we have thrown too much, nothing is lost."
Australians concerned about the wellbeing of friends and relatives have been urged to try to make contact with them directly. A 24-hour consular emergency hotline, 1300 555 135, has also been set up.
