US Secretary of State Ms Condoleezza Rice said Washington was ready to help Middle East peacemaking but the best outcome would be for Israelis and Palestinians to go on making progress on their own.
Criticised for too little involvement in Middle East peace efforts in his first term, President Bush has pledged to press harder to resolve the conflict in his next four years in office.
But speaking a day before she visits Israel for the first time as Secretary of State, Ms Rice said: "The United States wants very much for this to be a process that is the parties' process, that is owned by the parties, by the regional states.
"I hope we would all get into a mind-set that says if the parties are able to continue to move on their own that's the very best outcome," she told reporters en route to Ankara during an eight-day tour of Europe and the Middle East.
Ms Rice suggested Washington would play a more active role if peace efforts stuttered or US backing could clinch deals.
"When our involvement needs to take on a different character then we will do precisely that," said Ms Rice.
Israeli Prime Minister Mr Ariel Sharon and Mr Mahmoud Abbas, elected by Palestinians last month as Arafat's successor, will meet at a summit on Tuesday hosted by Egypt and attended by Jordan's King Abdullah.
Ms Rice will meet Mr Sharon and Mr Abbas before the summit but leave the region before it starts.
Her trip to the Middle East is likely to be dominated by a dispute over the release of Palestinian prisoners that Palestinians say must be resolved if Tuesday's summit in the Egyptian resort of Sharm el-Sheikh is to succeed.