The US secretary of state has said the upcoming Middle East peace summit must address substantive issues and advance the cause of a Palestinian state.
The US wants to support Mahmoud Abbas and isolate Hamas
Condoleezza Rice said there was no point inviting the Israelis and the Palestinians to the conference, expected in November, just for show.
Ms Rice made the comments after holding talks with Palestinian Authority President Mahmoud Abbas in Ramallah.
President Bush will meet Mr Abbas in New York on Monday.
A White House spokesman said discussions - to be held on the sidelines of the United Nations General Assembly meeting - would include issues related to the eventual creation of a Palestinian state alongside Israel.
The US has promoted a two-state solution, but the Israeli-Palestinian peace process has been stalled for most of the Bush administration.
Talks between Ms Rice and Mr Abbas were held a day after the Israeli cabinet declared Gaza a hostile entity.
The move, in response to continued rocket attacks by Palestinian militants in the coastal territory, could lead to the suspension of fuel and electricity supplies.
Mr Abbas and UN Secretary General Ban Ki-moon have condemned Israel's declaration.
At the meeting in the West Bank, Ms Rice tried to assure the Palestinian leader that the forthcoming conference would be focused.
"A successful meeting has to be one that is substantive and that advances the cause of the Palestinian state... and not one in which we simply meet for the sake of meeting," she told reporters afterwards.
Ms Rice said Mr Abbas and Israeli Prime Minister Ehud Olmert would draft a document before the conference that would "lay the foundations for serious negotiations".
The BBC's Middle East analyst Roger Hardy says the secretary of state will be aware that unless there is the prospect of real substance, the US will find it hard to get Arab states such as Saudi Arabia to attend.
Mr Abbas wants it to set out the framework for an agreement between the two sides, including a timetable leading to the creation of a Palestinian state.
Israel has so far resisted such a move.
The Palestinian leader is afraid that to attend a weak or inconclusive conference would play into the hands of his critics in the Islamist movement, Hamas, who are already confidently predicting the conference will be a waste of time, our correspondent adds.
On Thursday Israeli Prime Minister Ehud Olmert said his government would release more Palestinian prisoners soon - but gave no further details.
Meanwhile, 35 suspected Palestinian militants were detained by Israeli troops in the West Bank city of Nablus.
And in the Gaza Strip, two Palestinians died during a raid by Israeli forces. One was a youth crushed to death by an Israeli army bulldozer, the other was a militant.