The Red Cross says more than 27,000 flood-affected people in Papua New Guinea's Oro Province remain in desperate need of basic items like food and clean drinking water.
Floods hit the region last November.
The humanitarian agency says widespread flooding cause damage to food gardens, homes and other vital infrastructure.
The Red Cross secretary-general in PNG, Esmie Sinapa, told Radio Australia's program that the province's major rivers have all broken their banks.
"The most basic need at the moment is food because many of the gardens have been covered in water since November," Ms Sinapa said.
"So in some areas there will be food provided while in other areas the urgent need is for containers to store water."
The Oro provincial government has teamed up with the Red Cross to deliver disaster relief.
Provincial Governor Gary Zuffa has pledged more than $A230,000 to assist the Red Cross to carry out a relief operation.
Governor Zuffa says the Red Cross will also devise a Disaster and Risk Reduction plan for the province, with officials concerned about the province's ongoing vulnerability to natural disasters.
Mr Sinapa from the Red Cross says the plan will attempt to prepare communities for annual floods in order to reduce their impact.
"We cannot continue to provide relief each year in and year out," Ms Sinapa said.
"We must make sure that the communities are more prepared. This is a cyclical thing - they need to be able to take responsiblity themselves."
The Australian Kokoda Track Foundation is also raising funds to help the affected communities.
The foundation's executive director, Dr Genevieve Nelson, says they're making an urgent appeal to Australians for support.
Dr Nelson says the money will assist communities in the Sanananda-Buna-Gona region and around the Kumusi river.
© ABC 2013
10:34 EDT Thunderstorms have been few and far between in Australia's east over the past two weeks, but a trough is approaching and is set to linger for a week of lightning.