Suckling Tamanabae said the local government was stretched to the limit by the crisis and was appealing for help from national and international governments
"We have had some promises from the national government, but we have not received anything much in reality," he said, speaking from the provincial capital, Popondetta.
The rains were triggered by Cyclone Guba which has battered the region for several days.
Many villages have also seen their crops destroyed and the flooding forced the shutdown of water supplies in Popondetta.
Speaking from the capital, police spokesman David Terry told Al Jazeera that helicopters had only just made it through to the worst-hit parts of the province on Wednesday to begin initial assessments of the damage.
They have also begun to ferry in emergency food and medical supplies, although Terry said a "massive relief operation" was needed.
Disaster officials fear the death toll could rise significantly as dozens of residents from coastal and mountain villages are still missing after being washed away in surging flood waters, The Australian newspaper said.
|Heavy rains washed away bridges and roads |
leaving many communities cut off
Terry said there was a high risk of outbreaks of waterborne diseases such as malaria and cholera.
Popondetta's main airport and wharf had been closed for several days as a result of the heavy rains.
One Australian businessman based in Oro told Australian media he had seen scores of people living in canoes in "floating villages" after their homes were washed away.
Dale McCarthy told the Australian Associated Press said the crisis was on the brink of turning into a disaster affecting thousands of people.
"If we don't get food out to those people, it's going to be disease and famine for them," he said.
National authorities have declared a state of emergency in several provinces, airlifting police, rescue workers and food supplies to some of the worse-affected areas.
About 85 per cent of the six million people in Papua New Guinea rely on subsistence farming.
On Monday Michael Somare, the prime minister, convened an emergency cabinet meeting saying the flooding had affected about 145,000 people.
The governments of Australia and New Zealand, and other international aid agencies have said they are ready to send help once the extent of the disaster is known.