CANBERRA - Australia has told Israel that a major ground offensive in the southern Gaza city of Rafah would have a devastating impact.

In a statement posted on social media on Wednesday night, Australian Foreign Minister Penny Wong said the federal government had reiterated to Israel its objections to expanded military action in Rafah and its support for a ceasefire deal.

"More than half of Gaza's 2.3 million population are sheltering in Rafah, from the fighting elsewhere," Wong said.

"The impacts on Palestinian civilians from an expanded military operation would be devastating."

The Israel Defense Forces (IDF) on Monday ordered thousands of civilians in eastern Rafah to evacuate ahead of what it called a limited operation to eliminate Hamas fighters and dismantle infrastructure.

United Nations Secretary-General Antonio Guterres on Tuesday said a subsequent move by the IDF to seize the Palestinian side of the Rafah border crossing into Egypt would exacerbate an already dire humanitarian situation.

In a statement issued on May 3, the World Health Organization said it was deeply concerned a full-scale military operation in Rafah could lead to a bloodbath.

Wong on Tuesday said Australia's call remains for a humanitarian ceasefire to enable hostages to be released and unimpeded aid to flow.

She said the Australian government supports the ongoing work of Qatar, Egypt and the US to broker a deal.