OELWEIN, IOWA (AP) - Former vice-president Joe Biden said on Saturday (Dec 7) that it is "bizarre" for Senator Bernie Sanders to propose withholding United States military aid from Israel if the government there doesn't moderate its treatment of Palestinians.

The remarks highlight a nuanced but significant distinction between the Democratic presidential contenders. Mr Biden and Mr Sanders support a "two-state solution" for Israel and the Palestinians, and both men have criticised political leaders on each side of the longstanding conflict.

But Mr Biden's take, offered during a question-and-answer session with Iowa voters, hewed a more traditional US establishment line by reaffirming a financial commitment to Israel regardless of its actions toward Palestinians.

Mr Biden, while casting Israeli Prime Minister Benjamin Netanyahu as a "counterproductive" and "extreme right" leader, and accused Palestinian leaders of "fomenting" the conflict and "baiting everyone who is Jewish", suggested that some on the US political left give the Palestinian Authority "a pass" when criticising Israeli leadership.

"In terms of Bernie and others who talk about dealing with Zionism, I strongly support Israel as an independent Jewish state," he said in rural north-eastern Iowa.

He added: "The idea that I'd withdraw military aid, as others have suggested, from Israel, is bizarre. I would not do that. It's like saying to France, 'Because you don't agree with us, we're going to kick you out of Nato.'"

Mr Sanders, a Vermont senator, elevated the matter in late October when he said the US should "leverage" its billions of dollars in annual Israeli aid.

"My solution is to say to Israel: 'You get US$3.8 billion (S$5.1 billion) every year. If you want military aid, you're going to have to fundamentally change your relationship to the people of Gaza.' In fact, I think it is fair to say that some of that should go right now into humanitarian aid."

Mr Netanyahu said last Thursday, despite warnings from the International Criminal Court, that Israel has the "full right" to annex the Jordan Valley altogether if it chooses, and said he discussed annexation last week in a meeting with US Secretary of State Mike Pompeo.

The Palestinians seek all the West Bank, captured by Israel in 1967, as the heartland of their hoped-for state. The Jordan Valley comprises about a quarter of the West Bank and is one of the few open areas that could be redeveloped by the Palestinians. Israel counters that the area is vital to its security.

President Donald Trump's administration aligns closely with Mr Netanyahu, already recognising Israel's annexation of the Golan Heights.

Democrats, especially in the party's progressive flank, have become increasingly critical of Mr Netanyahu and the longstanding US alliance with the Jerusalem government.

Mr Biden on Saturday called it "a serious mistake, a fundamental mistake for the occupation of the West Bank now to become annexed property", and he chided Mr Netanyahu for a lurch to the "extreme right" as a means "to keep control".

But he had perhaps even harsher words for the Palestinian Authority, seemingly blaming them for a failure to reach new peace accords "and get 98 per cent of what they wanted" when President Barack Obama was then in office with Mr Biden as his top lieutenant.

"They continued to insist on baiting everyone who is Jewish, saying they would not sign a deal with a Jewish state, will not recognise one even if we have an independent nation," he said.

Mr Biden said that, as president, he'd continue to push Israel to accept a Palestinian state, but added that he's "tired of everybody giving the Palestinian Authority a pass... as if they're not continuing to foment all of this".