US Secretary of State Colin Powell says he wants to avoid arguments between Israel and the Palestinians over the details of the as-yet unpublished Middle East peace plan.
But Palestinian attacks on Israelis would make it "almost impossible" for US mediation to bring about progress on the plan, which envisages a Palestinian state by 2005, Mr Powell told Arab television stations in separate interviews.
The United States says it will release the peace plan or "road map" as soon as the Palestinian legislature confirms a new Palestinian Cabinet under Prime Minister-designate Mr Mahmoud Abbas, widely known as Abu Mazen.
US President George W. Bush said he expected the Middle East peace process to "accelerate and hopefully, greatly" and that he would invite Mr Abu Mazen, but not Palestinian President Yasser Arafat, to the White House.
Israel is expected to ask for changes in the "road map," but US officials say the United States will be reluctant to amend the plan.
"I don't want to spend a great deal of time arguing about the details of the road map. I want to see both sides . . . to start performing," Mr Powell said.
The Bush administration's earlier mediation efforts in the Middle East stalled last year when the White House agreed with Israel that Palestinian President Yasser Arafat was not doing enough to stop the violence.
The new arrangement with Mr Abu Mazen is meant to meet President Bush's demand for new Palestinian leadership, although Mr Arafat and Mr Abu Mazen have been close colleagues since at least the 1970s.
Palestinian negotiators have argued no Palestinian authority could guarantee complete security for Israelis. Setting a complete end to violence as a condition for negotiations gives a veto to extremists, they add.
Mr Powell also said he was working on a schedule for his controversial visit to Damascus, Syria, which is expected to take place some time in May.
The United States accused Syria this month of letting Arab volunteers into Iraq to fight US forces and failing to seal its border to fugitive Iraqi Baathists. Syria denied it.