Australia had been told to back up its stern words against Israel with action after a federal minister used a major international platform to warn against a full-blown assault in southern Gaza.
Finance Minister Katy Gallagher reiterated concerns about an increasingly dire humanitarian situation in the besieged strip and further devastation an invasion would have in Rafah, where more than one million civilians are sheltering.
"Australia believes this would be unjustifiable and we say again to Israel: do not go down this path," she told a G20 ministers meeting in Brazil while representing the foreign minister.
Senator Gallagher also tackled criticisms the G20 wasn't the right place to discuss geopolitical issues and should instead remain focused on economic matters.
"On the contrary, the people in this room - with over 30 country representatives - are exactly the right people to discuss the conflicts and tensions that have significant impacts on all our economies, affecting millions of people," she said.
Save the Children Australia CEO Mat Tinkler called on Australia to "back its words with action" as Israel signalled it would move ahead with the invasion regardless of international pressure.
This included reinstating funding to the United Nations Relief and Works Agency for Palestine Refugees, which Australiaze last month while it investigated allegations some staff were involved in Hamas' October 7 attack against Israel.
He also called for the government to boost humanitarian aid.
"The humanitarian situation reached catastrophic levels months ago and is deteriorating further every single day," he said.
Save the Children's global arm expressed alarm at the devastation and violence facing kids and called on all parties to the conflict to be added to the list of perpetrators of grave violations against children in armed conflict.
"Children in Gaza have been killed and maimed by Israeli forces at an unprecedented rate and scale, about 12,400 children have been killed and thousands more are missing, presumed buried under the rubble," CEO Inger Ashing said.
"Destruction of schools and hospitals in Gaza has become the norm, not the exception and children have suffered incalculable mental and physical harm."
The organisation also pointed to the 33 Israeli children killed and others abducted and held hostage by Hamas after the October 7 attacks "causing severe emotional and mental distress".
"Those responsible must be held to account ... and commit to implementing immediate actions to ensure the protection of children," Ms Ashing said, reiterating calls for a ceasefire.
Israel has intensified its bombardment of Rafah and the local health ministry has put the total Palestinian death count since Israel's response to Hamas' attack at nearly 30,000.
More than 1200 people died and up to another 200 were taken hostage on October 7, according to the United Nations.
Tel Aviv has pledged to continue its war against Hamas to root out militants and secure Israeli hostages, with more than 130 remaining in Gaza, according to Israel.
The way to free them was by ramping up the military pressure, Israel's finance minister said.
But the defeat of Hamas, designated a terrorist group by Australia, couldn't be at the expense of the "continuous suffering of all Palestinian civilians", Senator Gallagher said.
She again called for a humanitarian ceasefire, aid access and for Hamas to release all hostages.
International humanitarian aid organisation Act for Peace supported the government's call.
"Working together to achieve a sustainable ceasefire is required to provide safety for the one million people who have sought shelter in Rafah," CEO Elijah Buol said.
