Palestinian President Mahmoud Abbas has said that the United States is the only country that will prevent Israel from attacking the southern Gaza city of Rafah, where more than a million people have taken refuge.
Mr Abbas, who runs parts of the occupied West Bank, said any attack would see Palestinians flee Gaza.
Israel continues to vow to attack Rafah.
US President Joe Biden reiterated his clear position on Rafa to Israeli Prime Minister Benjamin Netanyahu in a call on Sunday.
The United States has repeatedly said it cannot support a large-scale Israeli military operation in Rafah without a credible plan to protect civilians from harm.
Speaking earlier at the World Economic Forum (WEF) in the Saudi capital Riyadh, Mr Abbas – who has no Palestinian Authority in Gaza under Hamas rule since 2007 – urged the US to intervene.
“We ask the US to ask Israel to stop the Rafah operation because the only country that can stop Israel from committing this crime is the US,” he said, adding that a “small attack” on Rafah would force the Palestinians to do so. People leaving the Gaza Strip.
“Then the greatest disaster in the history of the Palestinian people will happen.”
More than half of Gaza's population lives in Rafah, and conditions in the overcrowded southern city are already dire, with displaced people telling the BBC they lack food, water and medicine.
While the White House did not elaborate on Mr Biden's latest comments on the planned attack on Rafah, national security spokesman John Kirby told the ABC network that Israel had agreed to listen to US concerns and thoughts before entering.
US Secretary of State Anthony Blinken is due to arrive in Riyadh later on Sunday for talks with Mr Abbas.
Meanwhile, secret talks between Israel and Hamas over a possible cease-fire and the release of remaining hostages in Gaza have recently gained new momentum, further exposing divisions in Israel's ruling coalition.
If a fair deal to return the hostages is not agreed, the current government “will not have the right to continue,” war cabinet member and opposition figure Benny Kants said on Sunday.
“The entry into Rafah is crucial in the long struggle against Hamas. The return of the abductees is urgent and of great importance,” Mr Gantz X wrote earlier on Twitter.
However, far-right Finance Minister Bezalel Smodrich said he would have to resign if the government accepted the deal that canceled the planned offensive in Rafah.
Their comments came after Israel's foreign minister said a hostage deal could halt infiltration, which Mr Netanyahu has said would be the next step in its war against Hamas.
The Israeli military said its chief Herzi Halevi had approved plans to continue the war, which Israeli media said was a reference to the Rafah operation.
Long-running talks brokered by Egypt and Qatar have largely stalled because of gaps between Israeli and Hamas positions, but on Sunday Hamas said it would send representatives to Cairo to respond to the latest proposal.
Citing unnamed Egyptian officials, U.S. media reported that the latest ceasefire proposal offered to Hamas included weeks of peace aimed at ending the war, rather than freeing 20 hostages.
While Israel insists on the destruction of Hamas in Gaza and the release of all hostages, Hamas wants a permanent end to the war.
Egypt and other Arab countries cannot accept the influx of Palestinian refugees fleeing the war, as it amounts to expelling Palestinians from their land.
Satellite images show new tent camps being built near the Gaza Strip, west of Rafah and north of the town of Khan Younis, which are mostly left in ruins. Media reports said the tents were set up to house displaced people from Rafah.
The current war began when Hamas attacked Israeli communities near Gaza, killing around 1,200 people, mainly civilians, and taking around 250 hostages. Some 133 hostages are believed to still be in Gaza, of whom about 30 are presumed dead, with some freed after a brief standoff in November.
Israel's campaign of aerial bombardment and ground operations in Gaza since October 7 has killed 34,454 people, mostly civilians, according to the Hamas-run health ministry.
In a six-month war, the Israel Defense Forces (IDF) moved in and took control of all of northern Gaza, including Gaza City, and most of central and southern Gaza, including Khan Younis.
They have withdrawn from almost all areas, but troops remain on the Israeli-built road that separates northern and southern Gaza.
However, Palestinians who moved to southern Gaza – where the Israeli military said they had to go during the war for their own safety – could not return to their homes in the north, a key demand of Hamas in the ceasefire talks, with Israel not indicating when they would be allowed in.
Meanwhile, Israeli bombardment continued across Gaza, including Rafah, and the Israeli military said it was hitting launch sites for missiles.
