The United States has demanded that Israel proceed with plans for a unilateral withdrawal from the Gaza Strip and much of the West Bank.

U.S. officials said the Bush administration sent Israeli Prime Minister Ariel Sharon a message that called on him to continue with his proposal for a pullout from the entire Gaza Strip and much of the West Bank. They said the White House and State Department rejected the prospect that a Likud Party referendum that defeated Sharon's plan would end the Israeli initiative.

"The president placed a lot of diplomatic capital into the plan," a U.S. official said. "Sharon can come up with another initiative and another name, but we want some movement that is faithful to the president's vision of a two-state solution."

[On Tuesday, Sharon began meetings with senior Cabinet ministers to consider a new initiative regarding the West Bank and Gaza Strip. Sharon's largest coalition partner, Shinui, has urged the prime minister to resume efforts to reach agreement with the Palestinian Authority regarding an Israeli withdrawal.]

Officials said President George Bush and his aides were stunned by the Likud defeat of the Sharon plan and the prospect that any Israeli withdrawal would be shelved. They said the administration was persuaded by Sharon and his aides that the Likud Party membership would approve the plan.

Instead, Sharon's plan was solidly defeated in Sunday's referendum by a 60-40 margin. U.S. officials said the administration would press Sharon to advance the U.S.-supported roadmap, which calls for a Palestinian state with permanent borders in 2005.

"The president continues to believe that Prime Minister Sharon put forward a bold proposal that can help us move forward on the two-state vision that the president outlined," White House press secretary Scott McClellan said on Monday. "This can help us get moving again on the road map to help the Palestinian people realize a state of their own. And we have had some staff level contacts already with the government of Israel. And we'll continue to consult with Prime Minister Sharon and the government of Israel. And I expect that the government of Israel will have more to say in the coming days about how they intend to proceed."

On Tuesday, U.S. Secretary of State Colin Powell was expected to discuss the Likud defeat of the Sharon plan with other members of the so-called Quartet, responsible for the drafting of the roadmap. In addition to the United States, the Quartet includes the European Union, Russia and the United Nations.

"They again will look at where we are on the road map and look at ways to move forward on the president's vision," State Department spokesman Richard Boucher said.

Officials said they did not envision any crisis in U.S.-Israeli relations in wake of the Likud defeat of Sharon's plan. They said the White House has refused to send a letter to Jordan's King Abdullah that acknowledges Palestinian claims to the West Bank.

But some officials said Bush might reduce direct contact with the Israeli prime minister. They said that instead Powell would deal with high-level contacts with Israel until the November 2004 president elections.

"It'll be up to Prime Minister Sharon to decide how he proceeds within his party or within his government," Boucher said. "I suppose this is certainly a setback in what he had planned. But at the same time, we note that there is wide public support in Israel for the idea of moving forward and for the idea of withdrawing from Gaza."

On Tuesday, former U.S. diplomats and State Department officials announced a petition that urges Bush to reassess U.S. relations with Israel.

The diplomats plan to release the petition, drafted by former U.S. ambassador to Qatar, Andrew Killgore, at a news conference in Washington later in the day.

"Early responses are staggering," the American Education Trust, which helped organize the letter to Bush, said. "Signatories are united by their belief that the U.S. government is heading toward great danger. Our hope is that both political parties will take heed and listen to the voices of experienced diplomats."