Palestinian President Yasser Arafat has told the United States it would kill all hope of peace in the Middle East if it gave assurances to Israel on keeping West Bank settlements.
Israeli Prime Minister Ariel Sharon is in Washington to seek support for a plan to withdraw from Gaza, but keep Jewish enclaves in the West Bank where Palestinians also want a state.
Palestinians fear President George W. Bush will make landmark promises to Sharon that imply backing for Israel's occupation of land seized in the 1967 Middle East war and reject the eventual right of Palestinian refugees to return.
A statement from Mr Arafat's office said such an agreement would "lead to the destruction of the chances for the peace process and security and stability in the region. It will also restart the vicious cycle of violence in the region and end all the agreements and commitments that have been signed."
Mr Arafat urged rejection for any such deal from Arab states, Islamic countries and the world in general, saying it would violate international laws and cancel the "road map" peace plan that Bush has backed.
Commenting on the proposed Gaza pullout, Mr Arafat dismissed it as no more than a project to turn the territory into a "big prison" because Israel aims to keep control of borders as well as air and sea access.
"This deal which Sharon is seeking will take place at the expense of the Palestinian people and without the knowledge of the Palestinian people's legitimate leadership," the statement said.
President Bush has reiterated support for the road map, but Palestinians feel it would be rendered worthless if the United States gave guarantees to Israel on issues like the settlements and the right of Palestinian refugees to return.
Any perceived US endorsement of a cementing of Israel's hold on land Palestinians want for a state would inflame the Arab world and further complicate efforts to stabilize Iraq, where US forces are under daily attack from Muslim fighters.