The Palestinians are certain to win UN recognition as a state Thursday but success could exact a high price: Israel and the United States warn it could delay hopes of achieving an independent Palestinian state through peace talks with Israel.
The United States, Israel's closest ally, mounted an aggressive campaign to head off the General Assembly vote. Israeli Prime Minister Benjamin Netanyahu defiantly declared that the Palestinians would have to back down from long-held positions if they ever hope to gain independence.
In a last-ditch move, US Deputy Secretary of State William Burns made a personal appeal to Palestinian President Mahmoud Abbas promising that President Barack Obama would re-engage as a mediator in 2013 if Abbas abandoned the effort to seek statehood. The Palestinian leader refused, said Abbas aide Saeb Erekat.
Ahead of tonight's vote, thousands of Palestinians from rival factions celebrated in the streets of the West Bank. Although the initiative will not immediately bring about independence, the Palestinians view it as a historic step in their quest for global recognition.
In a statement, Mr Abbas appealed to all nations to vote in favour of the Palestinians "as an investment in peace."
"We remain committed to the two-state solution and our hand remains extended in peace," Mr Abbas said in a statement read by Palestinian Foreign Minister Riad Malki after the start of the General Assembly session in New York.
Mr Abbas is expected to address the assembly later.
With most of the 193 General Assembly member states sympathetic to the Palestinians, the vote is certain to succeed. Several key countries, including France, have recently announced they would support the move to elevate the Palestinians from the status of UN observer to non-member observer state.
However, a country's vote in favour of the status change does not automatically imply its individual recognition of a Palestine state, something that must be done bilaterally.
The Palestinians say they need UN recognition of a Palestinian state in the West Bank, Gaza and east Jerusalem, the lands Israel captured in 1967, to be able to resume negotiations with Israel. They say global recognition of the 1967 lines as the borders of Palestine is meant to salvage a peace deal, not sabotage it, as Israel claims.
The non-member observer state status could also open the way for possible war crimes charges against the Jewish state at the International Criminal Court.
Mr Netanyahu warned the Palestinians that they would not win their hoped-for state until they recognise Israel as the Jewish homeland, declare an end to their conflict with the Jewish state and agree to security arrangements that protect Israel.
"The resolution in the UN today won't change anything on the ground," Mr Netanyahu declared. "It won't advance the establishment of a Palestinian state, but rather, put it further off."
While Israel argues that Mr Abbas is trying to dictate the outcome of border talks by going to the UN, the recognition request presented to the world body in fact calls for a quick resumption of negotiations on all core issues of the conflict, including borders.
Mr Netanyahu's predecessors accepted the 1967 lines as a basis for border talks. Mr Netanyahu has rejected the idea, while pressing ahead with Jewish settlement building on war-won land, giving Mr Abbas little incentive to negotiate.
For Abbas, the UN bid is crucial if he wants to maintain his leadership and relevance, especially following the recent conflict between his Hamas rivals in Gaza and Israel. The conflict saw the Islamic militant group claim victory and raise its standing in the Arab world, while Mr Abbas' Fatah movement was sidelined and marginalised.
In a departure from previous opposition, the Hamas militant group, which rules the Gaza Strip, said it wouldn't interfere with the UN bid.
The US Congress has threatened financial sanctions if the Palestinians improve their status at the United Nations.
Unlike the Security Council, there are no vetoes in the General Assembly and the resolution to raise the Palestinian status from an observer to a non-member observer state only requires a majority vote for approval. To date, 132 countries - over two-thirds of the UN member states - have recognised the state of Palestine.