US won't supply weapons to Israel if it invades Gaza's Rafah city — Biden

President Joe Biden has said that US will not supply weapons or artillery shells to ally Israel if Tel Aviv invades southern Gaza's Rafah city, remarks that came after Washington decided to hold back delivery of high payload munitions to Israel, which it had been providing for the last seven months to support Tel Aviv's "genocidal" war on Gaza.

"Bombs that the US has supplied to Israel and now paused have been used to kill civilians," admitted Biden in an interview with CNN, adding Israel will not get US support "if they go into those population centres."

"I made it clear that if they [Israeli troops] go into Rafah — they haven't gone in Rafah yet — if they go into Rafah, I'm not supplying the weapons that have been used historically to deal with Rafah, to deal with the cities, that deal with that problem."

Biden, however, said the US was still committed to Israel's defence and would supply Iron Dome rocket interceptors and other "defensive" arms.

US declared its support for Israel since the beginning of the war on October 7 last year. US never held back in arming Israel regardless of alarming Gaza civilian casualties that hit 34,844 mark on Thursday — 70 percent of them babies, children and women. The United States gives Israel $3.8 billion in annual military dole and also shields its ally at the United Nations.

The interview marked Biden's toughest public comments yet about the potential Israeli military invasion and followed his decision to pause a shipment of heavy bombs to Israel last week over concerns that the US ally was moving closer to an attack on Rafah despite public and private warnings from his administration.

Israel has threatened an invasion on Rafah but Palestine, its allies and the United Nations say a full-scale invasion on the city, where some 1.5 Palestinian civilians are taking refuge, would further worsen Palestinians' condition and trigger a humanitarian catastrophe.

The shipment was supposed to consist of 1,800 2,000-pound (900-kilogramme) bombs and 1,700 500-pound (225-kilogram,e) bombs, according to a senior US administration official who spoke on the condition of anonymity to discuss the sensitive matter.

The focus of US concern was the larger explosives and how they could be used in a dense urban areas.

Austin on weapons delay

US Defense Secretary Lloyd Austin earlier on Wednesday confirmed the weapons delay, telling the Senate Appropriations subcommittee on defence that the US paused "one shipment of high payload munitions."

"We're going to continue to do what's necessary to ensure that Israel has the means to defend itself," Austin said. "But that said, we are currently reviewing some near-term security assistance shipments in the context of unfolding events in Rafah."

Austin said that Israel had to be more precise and the type of weapons used in a heavily populated area mattered.

A "small-diameter bomb, which is a precision weapon, it's very useful in a dense, built-up environment... but maybe not so much a 2,000-pound bomb that could create a lot of collateral damage," Austin said.

Israel's war on Gaza has left almost all of Gaza's 2.4 million people on the brink of starvation and sparked US protests calling for universities and Biden to withdraw support from Israel — including weapons.

Democrats, including some lawmakers in his party, are also demanding Biden put more pressure on Israel.

Israel is accused of genocide at the International Court of Justice. Francesca Albanese, the UN special rapporteur on the rights situation in the Palestinian territories, says there were reasonable grounds to believe Israel is committing genocide against Palestinians in Gaza.