The Palestinian president has warned that US recognition of Jerusalem as Israel's capital would jeopardise the White House's nascent Mideast peace efforts.
President Mahmoud Abbas' comments came amid a diplomatic push by the Palestinian leader to rally international support against the possible US move later this week.
"Any American step related to the recognition of Jerusalem as capital of Israel, or moving the US embassy to Jerusalem, represents a threat to the future of the peace process and is unacceptable for the Palestinians, Arabs and internationally," Mr Abbas told a group of visiting Arab politicians from Israel, according to the official Wafa news agency.
US officials have said President Donald Trump may recognise Jerusalem as Israel's capital this week as a way to offset his likely decision to delay his campaign promise of moving the US embassy there.
Israel regards Jerusalem as its capital, with most government functions, including the prime minister's office, Supreme Court and parliament, located in the holy city.
But the international community says the city's status should be determined through peace talks. The Palestinians claim east Jerusalem, captured by Israel in 1967, as their capital.
Abbas' spokesman, Nabil Abu Rdeneh, said late Saturday that the president had been in touch with Arab and world leaders to rally opposition against any US move on Jerusalem.
He said Mr Abbas had been in contact with leaders of Egypt, Jordan, Saudi Arabia, Qatar, Kuwait and France.
"We believe that such an American step, if it takes place, will enter the region in a new course, and a dangerous phase whose results cannot be controlled," he said.
The White House, led by Mr Trump's adviser and son-in-law, Jared Kushner, has held months of meetings with leaders across the region ahead of an expected peace initiative.
While the proposal is expected to be regional in scope, little is known about the details, including whether Mr Trump will continue the policies of recent predecessors in supporting the notion of an independent Palestinian state.
Mr Kushner said Sunday that Mr Trump has not yet decided whether to recognise Jerusalem as Israel's capital or whether to proceed immediately in moving the US embassy from Tel Aviv to the holy city.
"He is still looking at a lot of different facts," Mr Kushner said at the Saban Forum, an annual Mideast policy conference in Washington.
Ahead of Mr Kushner's comments, the chief Palestinian negotiator, Saeb Erekat, urged the US not to move forward with any change on Jerusalem's status.
Doing so, he said, "is not only going to promote international anarchy and disrespect for global institutions and law, but it will also be disqualifying itself to play any role in any initiative toward achieving a just and lasting peace".