The Bush administration said that its endorsement of Israel's withdrawal plan from Gaza in no way prejudges the outcome of future negotiations for a Palestinian state.

State Department spokesman Richard Boucher faced repeated questions from reporters Tuesday about the impact of America's backing of Israeli Prime Minister Ariel Sharon's plan to dismantle some Israeli settlements while retaining others, specifically, whether so-called "final status" negotiations for the Palestinians have been rendered moot. Mr. Boucher said that nothing has been ruled in or out of future dialogue.

"We [the United States] do not determine what the parties bring into the negotiations, and, ultimately, we do not determine what the parties bring out of negotiations," he said. "Our role has consistently been to try to help the parties achieve their aspirations. Frankly, I would say our role has been to try to help the Palestinians achieve their aspirations through negotiations."

Asked whether the Bush administration can be an impartial mediator, Mr. Boucher said that the United States has never been entirely neutral on every issue concerning the Middle East peace process. Rather, he said, the United States has tried to be helpful in facilitating an outcome that benefits all parties.

The spokesman was blunt when addressing the issue of what the Palestinians' next move should be.

"The answer to building a state is to build a state. The Palestinians are about, if we can make this work right, are about to take back territory completely under their control, about to see for the first time in decades the withdrawal of Israelis from settlements, from territories that the Palestinians should have to administer," Mr. Boucher said. "It is time for the Palestinians, like the rest of us, to focus on making that disengagement work."

Mr. Boucher added that to make Israeli disengagement work, Palestinians must build the institutions of state, focusing on internal security, economic matters, education and healthcare.