In a further sign of world concern over the conduct of the conflict, now in its third month, Australia, Canada and New Zealand said they supported international efforts towards a sustainable ceasefire.

They expressed alarm at the plight of civilians in Gaza.

At the United Nations, the 193-member UN General Assembly was preparing to vote on a resolution calling for a ceasefire.

Diplomats said it was expected to pass. The United States vetoed a similar call in the 15-member Security Council last week.

Biden said Israel now has support from “most of the world” including the US and European Union.

“But they’re starting to lose that support by indiscriminate bombing that takes place,” he told a campaign fundraising event in Washington.

Israel’s assault on Gaza to root out Hamas has killed at least 18,205 Palestinians and wounded nearly 50,000 since October 7, according to the Gaza health ministry.

Many more dead are uncounted under the rubble or beyond the reach of ambulances.

Israel launched its onslaught in response to a cross-border raid by Hamas fighters who killed 1,200 people and took 240 hostage in southern Israel on October 7.

In Khan Younis, southern Gaza’s main city, residents said on Tuesday Israeli tank shelling was focused on the city centre.

One said tanks were operating in the street where the house of Yahya Al-Sinwar, Hamas’ leader in Gaza, is located.

Further south in Rafah, which borders Egypt, health officials said 22 people including children were killed in an Israeli air strike on houses overnight.

Civil emergency workers were searching for more victims under the rubble.

Residents said the shelling of Rafah, where the Israeli army this month ordered people to head for their safety, was some of the heaviest in days.

Washington has shared Israel’s position that a ceasefire would only benefit Hamas.

But as well as warning that Israel was starting to lose international support, Biden said Netanyahu needed to change his hardline government.

The leaders of Australia, Canada and New Zealand said in a joint statement they were alarmed at the diminishing safe space for civilians in Gaza.

“The price of defeating Hamas cannot be the continuous suffering of all Palestinian civilians,” they said.

The three countries also said they supported Palestinians’ right to self-determination, but there could be no role for Hamas in the future governance of Gaza.

Biden also said that ultimately Israel “can’t say no” to an independent Palestinian state – something that Israeli hardliners oppose.

Israel’s military said that in the past day it hit several posts that were used to fire rockets at its territory, raided a Hamas compound where it found about 250 rockets among other weapons and struck a weapons production factory.

The ground assault that started in the north has expanded to the southern half of the Gaza Strip since a week-long truce collapsed at the start of December.

More than 100 Israeli soldiers have been killed in Gaza since the ground invasion began in late October.

The Wall Street Journal reported the Israeli military has begun pumping sea water into Hamas’ tunnel complex, where the militant group is believed to be hiding hostages, fighters and munitions and using it to wage hit-and-run attacks on Israeli troops in street fighting.

Gaza health ministry spokesman Ashraf Al-Qidra said Israeli forces had raided Kamal Adwan Hospital in northern Gaza on Tuesday and detained its director, Dr Ahmed Al-Kahlout, along with all medical staff including female teams.

They were being interrogated within the emergency department, he said. Israel’s military did not reply to a request for comment on the incident.

The UN World Food Programme says half of Gaza’s population is starving as Israel has cut off supplies of food, medicine and fuel.

The UN humanitarian office OCHA said on Tuesday limited aid distributions were taking place in the Rafah district, but in the rest of the Gaza Strip, aid distribution had largely stopped due to the hostilities and restrictions on movement on roads.

– AAP