The New Zealand Red Cross says people in the flood stricken areas of Papua New Guinea are in need of clean drinking water, food and temporary shelter.
Thousands of people have lost their homes following the severe flooding.
A spokesperson for the aid agency, Rosemarie North, who is in hard-hit Popondetta, says the situation there is dire and people need clean drinking water urgently.
"The main things we are worried about are food, water and shelter. We have just started digging a trench and it's going to run 350 metres from the river up to the hospital. We have got a Australian filter and disinfection unit and the plan is to pump water from the river up to the hospital."
Rosemarie North says people also need tarpaulins to build emergency shelters as it could take months until they can rebuild their homes.
The death toll from the floods has been put at more than 200.
Meanwhile, Australia's aid organisation, AusAID, says it may have to help feed tens of thousands of villagers for months.
Australian Army Black Hawk helicopters have spent the past few days dropping urgently needed supplies to flood victims in hard hit Oro Province.
AusAID field coordinator, Bill Costello, says it could be looking at several months of feeding most of the population of this province.
He says relief flights were being focussed on one of the hardest hit areas along the Kumusi River.
Mr Costello says cases of diarrhoea, dysentery and malaria had already been reported.