Israeli Prime Minister Benjamin Netanyahu said on Thursday he was ready to work with Joe Biden for the rest of his presidency, as the two leaders met for the first time at the White House for talks on a Gaza ceasefire.

"I want to thank you for the 50 years of public service and 50 years of support for the state of Israel," Netanyahu said after they shook hands in the historic setting of the Oval Office.

"And I look forward to discussing with you today and working with you in the months ahead."

Biden stunned the world on Sunday when he announced that he was bowing out of the US presidential election, with Vice President Kamala Harris now set to be the Democratic Party's candidate.

Netanyahu will also meet Harris separately at the White House, in a reflection of the new political reality that will see Biden as a lame duck president for his remaining six months in office.

The Harris meeting comes amid speculation that if she wins in November it could herald a tougher approach on Israel's war in Gaza.

Relations between Biden and Netanyahu are tense over Israel's conduct in the war sparked by Hamas's October 7 attacks, but the US president has continued strong military and political support.

They have met just three times during his presidency, once in September last year in New York, and then when Biden travelled to Israel after the attacks and hugged Netanyahu on the airport tarmac at Tel Aviv.

The meetings come after Netanyahu vowed "total victory" against Hamas in a fiery speech Wednesday to the US Congress.

Biden and Netanyahu will later meet the families of US hostages held in Gaza.

The White House was surrounded by metal barriers and a heavy police presence, after rowdy protests broke out near the Capitol following Netanyahu's speech.

Harris on Thursday condemned the "despicable" and "unpatriotic" burning of an American flag by protesters, after attempts by Donald Trump's Republicans to paint Democrats as pro-Hamas.

In a primetime speech explaining his decision on Sunday to bow out of the US presidential election, Biden made clear that resolving the conflict would remain a top priority.

"I'm going to keep working to end the war on Gaza, bring home all the hostages to bring peace and security to the Middle East and end this war," the US president said.

A senior US administration official said on Wednesday that negotiations on a Gaza deal were in the "closing stages" and that Biden would try to close some "final gaps" with Netanyahu.

Harris has previously been more outspoken about Israel's conduct of the war, prompting speculation she will shift her policy as presidential nominee.

The US official said there was "no daylight between the president and vice president," who will meet Netanyahu at 4:30 pm (2030 GMT).

Netanyahu will meet Republican contender Donald Trump on Friday at his Mar-a-Lago residence in Florida.

The ex-president on Thursday morning urged Israel to quickly "finish up" its war in Gaza, warning its global image was being tarnished.

Biden has offered Israel steadfast support since October 7.

But the US president has been increasingly critical of Israel over the Palestinian death toll in its offensive in Gaza, and criticised restrictions on the amount of aid getting through to the territory, much of which has been reduced to rubble.

The Hamas attack on October 7 resulted in the deaths of 1,197 people in Israel, most of them civilians, according to a tally based on official Israeli figures. Out of 251 people taken hostage that day, 111 are still being held inside the Gaza Strip, including 39 who the military says are dead.

More than 39,100 Palestinians have been killed in Israel's military campaign in the Gaza Strip since the war began, according to data provided by the health ministry of Hamas-run Gaza, which does not give details of civilian and militant deaths.

According to the Israeli military 327 soldiers have been killed in the Gaza military campaign since the start of the ground offensive on October 27. (AFP)