'You carpet bombed Germany, you dropped atom bomb': Netanyahu tells Biden

US President Joe Biden has said that Israeli Prime Minister Benjamin Netanyahu needs to change his hardline government and that Israel cannot say no in the future to a Palestinian state, ramping up pressure on the Israelis while Netanyahu hit back with "atom bomb" on Japan comment.

Biden's remarks at a fundraising event for his 2024 re-election campaign came after US sold 14,000 tank shells to Israel without Congress review and also scuttled a UNSC vote that would have called for a ceasefire in Israel's war on Gaza.

Biden falsely claimed that Israel had "most of the world supporting it", despite global protests since October 7 and member states at UN Security Council and UN General Assembly overwhelmingly demanding Israel end its brutal war in Gaza.

"But they're starting to lose that support by the indiscriminate bombing that takes place," Biden said.

The sharp comments came as Biden's national security adviser, Jake Sullivan, prepares to travel to Israel for talks with the Israeli war cabinet.

Biden specifically mentioned Israel's far-right politician Itamar Ben-Gvir, who is Israel's national security minister, and said "this is the most conservative government in Israel's history."

"He [Netanyahu] has to change this government. This government in Israel is making it very difficult," Biden said. He also said that ultimately Israel "can't say no" to a Palestinian state, which Israeli hardliners oppose.

Biden alluded to a private conversation in which the Israeli leader said: "'You carpet bombed Germany, you dropped the atom bomb, a lot of civilians died.'"

Biden said he responded: "Yeah, that's why all these institutions were set up after World War Two to see to it that it didn't happen again ... don't make the same mistakes we made in 9/11. There's no reason why we had to be in a war in Afghanistan."

Netanyahu said in a statement on Tuesday that Israel had received "full backing" from the US for its ground invasion into Gaza and that Washington had blocked "international pressure to stop the war."

Israel has occupied the West Bank since the Six-Day War of 1967. It maintains a harsh siege of Gaza since 2005 and is now invading it. The occupied West Bank is home to nearly three million Palestinians, as well as around 490,000 Israelis who live in settlements considered illegal under international law.

'You cannot say no Palestinian state'

Biden said "we have an opportunity to begin to unite the region... and they still want to do it. But we have to make sure that Bibi understands that he's got to make some moves to strengthen... You cannot say no Palestinian state... That's going to be the hard part."

Sullivan said on Tuesday that during his visit to Israel he will discuss with Israeli officials their timetable for the war in Gaza.

"The subject of how they are seeing the timetable of this war will certainly be on the agenda for my meetings," said Sullivan, who is expected to travel later this week.

Israel has bombarded Gaza from the air, imposed a siege and launched a ground invasion since October 7, killing about 18,205 Palestinians and wounding nearly 50,000 others.

Most of the 2.3 million people in Gaza have been driven from their homes by Israel and the United Nations has given dire warnings about the humanitarian situation in the coastal enclave, saying that hundreds of thousands of people are starving.