Prime Minister Malcolm Turnbull has rejected calls from some coalition MPs to temporarily suspend foreign aid and divert the cash to help flood-stricken communities in Queensland and NSW.
Ex-Tropical Cyclone Debbie has flooded parts of Queensland and northern parts of NSW.
Mr Turnbull acknowledged many people were grappling with the tragedy and loss. Five people have died and three are still missing.
He said substantial relief was being delivered by the federal and state governments to the affected communities.
Watch: Rockhampton residents count costs of flood
"We are a generous and responsible foreign aid donor and it is a very important part of our international diplomacy."
It was also an important part of being a responsible and effective global citizen, he told reporters in Port Moresby.
Papua New Guinea is Australia's largest aid recipient receiving just under half a billion dollars a year.
Australian aid money in PNG is helping to stop the spread of the deadly tuberculosis, help domestic violence victims access counselling and support and building children's classrooms.
The distance between PNG and Boigu Island in the Torres Strait near far north Queensland is about five kilometres, and experts have long feared the biosecurity risk of drug-resistant tuberculosis spreading south.
In Papua New Guinea, 28 per cent of the population lives below the poverty line.
Lismore-based Nationals MP Kevin Hogan says he believes charity should begin at home.
"Once areas are rebuilt, foreign aid can be reinstated," he told the Northern Star newspaper.
"There is a lot of money which will flow to the disaster areas, but it should not be at the expense of other domestic priorities or increased debt."
