US Secretary of State Hillary Clinton said Wednesday that the only path towards a Palestinian state was through direct negotiations, on the eve of a contentious United Nations vote.

"I have said many times that the path to a two-state solution that fulfills the aspirations of the Palestinian people is through Jerusalem and Ramallah, not New York," Clinton told reporters, reiterating US opposition to the Palestinian bid to upgrade its UN status.

"We have made very clear to the Palestinian leadership that we oppose Palestinian efforts to upgrade their status at the UN outside of the framework" of direct negotiations.

The top US diplomat warned that no matter what happened on Thursday at the United Nations "it will not produce the outcome" that everyone desires.

"The only way to get a lasting solution is to commence direct negotiations," Clinton stressed.

"And we need an environment conducive to that and we urged both parties to refrain from actions that might, in any way, make a return to meaningful negotiations that focus on getting to a resolution more difficult."

The United States earlier Wednesday pressed Palestinian president Mahmud Abbas not to seek elevated UN status, in a last-ditch bid to avert a damaging showdown at the United Nations.

US Deputy Secretary of State William Burns and Middle East envoy David Hale met with Abbas at his hotel but failed to get the Palestinian leader to withdraw his resolution or make amendments, officials said.

US officials have reaffirmed that the United States will vote against the Palestinian motion if the vote goes ahead as planned on Thursday.