Anthony Albanese used some of his strongest language yet to condemn the blockade of food and supplies into the territory, as Israel begins to let in just a trickle of humanitarian aid after a nearly three-month blockade.
More than two million people in the strip face starvation and famine.
Mr Albanese said Israel's actions were "completely unacceptable" and that he raised the issue with Israeli President Isaac Herzog when they met on the sidelines of the Pope's inauguration in Rome last week.
"I made it very clear that Australia finds these actions completely unacceptable and we find Israel's excuses and explanations completely untenable and without credibility," he told reporters in Canberra on Monday.
"It's outrageous that there'd be a blockade of food and supplies to people who are in need in Gaza.
"People are starving and the idea that a democratic state withholds supply is an outrage."
Using starvation as a warfare method is a war crime, according to international law experts.
Mr Albanese reiterated Australia's support for a ceasefire and for the designated terrorist organisation Hamas to return Israeli hostages.
"We consistently and unequivocally oppose what happened on October 7, but states, which are democratic states, have a responsibility to behave in a way that is consistent with international law and with humanitarian concerns," he said.
"The whole world is concerned about what has occurred with the blockade."
Australians are largely in step with the prime minister, with about four in five people saying Israel's deliberate hindrance of humanitarian aid isn't justifiable, according to YouGov polling commissioned by a number of not-for-profit organisations.
Two-thirds of respondents said Australia should do more to support civilians in Gaza who cannot access food, water or medicine, the survey of 1500 people found.
Support was highest amongst Labor voters for both statements.
Some 9000 trucks are waiting to enter Gaza, Oxfam Australia's acting chief executive Chrisanta Muli said.
"The small amount we've seen so far enter Gaza represents a trickle of water into an ocean of need," Dr Muli said.
"Australians want our government to take a stronger stance to halt the devastating destruction of Gaza and its people.
"They are clearly saying, 'the current status quo is unacceptable'."
The survey was commissioned by Oxfam Australia, ActionAid Australia, Plan International Australia, Union Aid Abroad-APHEDA, Caritas and ChildFund Australia.
Australia has also condemned the forced displacement of Palestinians as Israel reinvigorates its military offensive in the strip.
The Israeli military controls about 77 per cent of Gaza, according to Gazan officials.
The strip has been largely reduced to rubble and Israel's counteroffensive has left more than 53,000 people dead, according to the local health ministry.
It followed Hamas' attack against Israel on October 7, 2023 which killed 1200 people and resulted in 250 people taken hostage, according to Israel's tallies.
Dozens of hostages remain captive and Israel began its blockade and restarted a ground offensive after a ceasefire deal collapsed months ago.
The deal resulted in the release of 25 hostages held by Hamas and about 1900 Palestinian prisoners held by Israel.
