The full extent of the destruction from last week's 9.0 magnitude earthquake and tsunami in Japan is still becoming clear, as rescuers comb through the damaged northeast region.
The latest official death toll has risen to nearly 3400, but it is feared at least 10,000 people may have been killed.
More than half a million people are living in temporary shelters short of food, water and fuel - and more freezing weather and snow is forecast.
The director of Medecins Sans Frontieres in Japan, Eric Ouannes, says even the most organised aid groups are having difficulty reaching some areas.
He says pockets of people have not yet received any aid, in areas with remote and difficult access where roads and infrastructure have been destroyed.
The main roads into the region have been mostly cleared and the army is also using helicopters to bring in basic supplies.
Hundreds of aftershocks have rattled the country since Friday, including a magnitude 6 one on Wednesday. No tsunami warning was issued.
New Zealander still missing
The Ministry of Foreign Affairs is still trying to track down a New Zealander for whom it has grave fears.
The ministry says it has confirmed 1825 of the estimated 6000 New Zealanders in Japan are safe.
The ministry had fears for another man Steven Brooking, but he has since been found safe and well.
The Miyako school where Mr Brooking was teaching was swamped by Friday's tsunami.
Mr Brooking's father Gary Brooking says his son has since managed to contact the ministry, but he hasn't been able to speak with him directly yet because the phone he was using has gone flat.
New Zealander staying put
One New Zealander in the quake zone plans to stay put in Japan, despite the devastation of the tsunami and the risk from a damaged nuclear power plant.
When the earthquake and tsunami struck on Friday, Nick Williams was within 60 kilometres of the Fukushima plant, teaching English as part of an exchange programme.
Mr Williams says he banded together with other members of the programme and escaped to Aizu Wakamatsu, which he says is shielded from any nuclear fallout by mountains and still has power and water.
The town is packed with refugees, he says, with up to nine people in each apartment.