Foreign Affairs Minister Murray McCully says there is growing concern for New Zealanders in Japan who were in areas where tsunami waters have washed away entire villages.
"Those are the ones we are giving priority to try to isolate," he said today.
New Zealand officials have scrambled to try to contact ex-pats in Japan since a devastating 9.0 magnitude quake hit the country on Friday and a resulting tsunami flooded large swathes of land with 10m high waves.
Finding all missing New Zealanders would be a "long, slow process" as many people would be on the move, but Mr McCully said hopefully they would know more in the next few days.
There were 871 New Zealanders registered with MFAT as being in Japan.
The New Zealand death and injury toll remained at zero, an MFAT spokesman said, but staff in Wellington and Japan were making continued efforts to contact a small number of New Zealanders in the affected areas to determine their whereabouts and safety.
Mr McCully said flights were getting out of Japan in a timely fashion, so people wanting to leave the country should be able to, so long as they were not in an area so badly damaged that travel was impossible.
New Zealand's 46-strong urban search and rescue team (USAR) arrived in Japan today ready to help search for survivors of the disaster.
The Japanese Government was "delighted" to have the team there to help assist their own emergency services, Mr McCully said.
"They're very conscious of the fact that these are guys who have just been doing some very difficult work here (in Christchurch), so the fact that New Zealand has sent them means a good deal to them."
The USAR team was supported by five Defence staff and an MFAT representative.
The group would be working in the Sendai area with the Australian, German and Swiss USAR teams. They were assembled at the USA military base at Yokota near Tokyo.
NZ Fire Service national manager special of operations, Jim Stuart-Black, said they would be a safe distance from the Fukushima Daiichi nuclear power plants, which have been leaking radiation since explosions have ripped through the facility.
"The team will be well outside the current evacuation area. As an added precaution, everyone went through refresher training in managing and monitoring radiation exposure before they left. We all also have protective suits and respirators with us."
MFAT has advised against all tourist and non-essential travel to Tokyo due to disruptions to essential services such as transport and electricity, and also recommended against tourist and non-essential travel to the earthquake and tsunami affected areas in the northeast.
Prime Minister John Key expected the quake and tsunami to have an adverse impact economically.
"It's going to have some impact... it's a big market from our point of view."
That disaster was also likely to impact on the cost of New Zealand's reinsurance bill.
"The reinsurers are taking a hammering at the moment."
It was hard to say what the impact would be from Japan but already New Zealand's quake would prompt premium increases.
Mr Key said New Zealand's reinsurance was less than $1 billion.
"It's not a hell of a lot."
