Palestinian President Mahmoud Abbas says the US is the only country that can stop Israel from attacking Rafah, the southern Gaza city where more than a million people are taking refuge.
Mr Abbas, who runs parts of the occupied West Bank, said any attack could see Palestinians flee Gaza.
Israel has consistently vowed to carry out an offensive in Rafah.
US President Joe Biden “reiterated his clear position” on Rafah to Israel PM Benjamin Netanyahu in a call on Sunday.
The US has repeatedly said it cannot support a large-scale Israeli military operation in Rafah without seeing a credible plan to keep civilians out of harm’s way.
Speaking at the World Economic Forum (WEF) in the Saudi capital Riyadh earlier, Mr Abbas – whose Palestinian Authority is not present in Gaza, which has been under Hamas rule since 2007 – urged the US to intervene.
More than half of Gaza’s population is in Rafah and conditions in the overcrowded southern city are already dire, with displaced people there telling the BBC there was a lack of food, water and medication