Peter Dutton has backed Israel's war on Hamas as the nation prepares for a major ground offensive at Rafah in southern Gaza.
The federal opposition leader made the remarks in response to a joint leaders' statement from Australia, Canada and New Zealand.
They warned a ground invasion of the city would be catastrophic, with more than one million Palestinians there seeking refuge.
Civilians could not be made to pay the price of defeating Hamas, they said.
Mr Dutton said Hamas was to blame for the tragedy.
"Israel has provided a response to make sure their country is secure," he said on Friday.
"We want an end to the conflict as quickly as possible but that can't happen until the terrorists release those children in particular, those women, and the other hostages."
More than 1200 people were killed and 240 others taken hostage when Hamas attacked Israel on October 7, in what the Australian government has declared a terror event.
Israel's subsequent war on Gaza has killed more than 27,000 Palestinians and wounded another 66,000 people, according to the UN and local health ministry.
Prime Minister Anthony Albanese has repeatedly raised concerns about Israel's planned attack on Rafah, saying there was nowhere for civilians to go.
"The consequences of an invasion are dire," Mr Albanese said.
Australia is being urged to immediately reinstate aid for Palestinian refugees.
The federal government must reject propaganda attacks against the United Nations Relief and Works Agency for Palestinian Refugees, the nation's peak foreign aid organisation said.
Israel had a clear motive in wanting to disband the organisation, Australian Council for International Development chief executive Marc Purcell said.
"This is the UN agency that is currently on the ground providing lifesaving support in Gaza, so this reality is important and disturbing," he said.
"We urge greater skepticism by Australian parliamentarians and the media in the face of what is now a well-established pattern of Israeli government making shrill and spurious accusations."
Australia and other international partners froze aid to the relief agency following allegations some of its staff participated in Hamas' October 7 attack.
The federal government is awaiting a UN investigation into the claims, but says Israel has not provided any evidence to support its allegations.
Australia has also been urged to commit to a national debate about a two-state solution to the Israeli-Palestinian conflict.
The Palestinian envoy to Australia said the path to a two-state solution wasn't working, after the Israeli prime minister doubled down on his opposition.
Australia does not recognise a Palestinian state but has committed to doing so.
Envoy Izzat Abdulhadi urged the Albanese government to act.
"I'm sure there is interest in the leadership here," he told AAP.
