Former US president Donald Trump warned Israel in an interview published Monday that it was losing support over the war in Gaza, reiterating his call to "finish it up".

The comments from Trump, the presumptive Republican nominee to take on President Joe Biden in November's US election, came as Washington abstained at a UN Security Council vote calling for an immediate ceasefire in the Israel-Hamas war.

"You have to finish up your war. To finish it up. You gotta get it done," Trump told the Israel Hayom newspaper in an interview the right-wing freesheet said had been recorded over the weekend.

"And I will say, Israel has to be very careful, because you're losing a lot of the world, you're losing a lot of support, you have to finish up, you have to get the job done."

Trump frequently touts himself as a devoted ally of Israel, pointing to his decision to move the US embassy to Jerusalem and his administration's role in brokering the 2020 Abraham Accords which saw Arab countries including the United Arab Emirates and Bahrain normalise ties with Israel.

Palestinians, who claim Israeli-annexed east Jerusalem as their future capital, have opposed Trump's policies.

The former president has also lashed out at Democratic politicians including Senate Majority Leader Chuck Schumer for criticising Israeli Prime Minister Benjamin Netanyahu.

"I think it's a terrible thing to do," Trump said of recent remarks by Schumer calling for early elections in Israel.

The war in Gaza was triggered by Hamas's unprecedented October 7 attack on southern Israel which resulted in the deaths of about 1,160 people, mostly civilians, according to an AFP tally of official Israeli figures.

Israel's retaliatory military campaign to destroy Hamas has killed 32,333 people, mostly women and children, according to the health ministry in the Hamas-run territory.

Trump told Israel Hayom he would have responded to Hamas's attack "very much the same way" Israel did, but expressed concern about the optics of a war in which Israeli strikes have left much of Gaza in ruins.

"I think that's one of the reasons that there has been a lot of kickback," Trump said, arguing the Israeli military should not have released footage of its strikes.

"If people didn't see that, every single night I've watched every single one of those. And I think Israel wanted to show that it's tough, but sometimes you shouldn't be doing that."