If Israeli Prime Minister Ehud Olmert fails to negotiate, the Palestinians may weigh "alternative action on the ground," DEBKAfile, a military intelligence Web site based in Jerusalem, reported in an exclusive story.

Abbas has warned U.S. President George Bush and Secretary of State Condoleezza Rice of his position, the Web site said.

This is Abbas' second threat to reignite the Palestinian-Israeli war. He told the Arabic newspaper Ad Dustour , that even though he prefers negotiations for now, he wouldn't dismiss an alternative option in the future.

The Palestinian leader's conditions for talks to proceed include Foreign Minister Tzipi Livne satisfying Palestinian opposition's demands for a final list of Israeli concessions on issues of borders, refugees, Jerusalem and water. Abbas maintain Israel must stop construction in Jerusalem and the settlements, Washington sources told DEBKAfile.