Reuters reports that the countries made the call on Thursday in a joint statement released in response to reports about Israel's planned military operation in Rafah.
The Canadian, Australian and New Zealand authorities have called for an immediate humanitarian ceasefire in Gaza by Israel in the ongoing Israeli-Hamas war.
The statement jointly signed by the prime ministers of the three countries stated, "We are gravely concerned by indications that Israel is planning a ground offensive into Rafah. A military operation into Rafah would be catastrophic.
"An immediate humanitarian ceasefire is urgently needed."
But Reuters reports that the Israeli Prime Minister, Benjamin Netanyahu, said on Wednesday that Israel will press ahead with an offensive against Hamasin Rafah, the last refuge for displaced Palestinians in southern Gaza, after allowing civilians to vacate the area.
However, the three countries in the statement urged Israel not to conduct the offensive, but noted that any ceasefire could not be "one-sided," and would require Hamas to disarm and immediately release all remaining hostages.
The leaders of the three countries also said the International Court of Justice's January ruling in a genocide case brought by South Africa obligated Israel to protect civilians and deliver basic services and essential humanitarian assistance.
They said, "The protection of civilians is paramount and a requirement under international humanitarian law," adding that "Palestinian civilians cannot be made to pay the price of defeating Hamas."