The leaders, meeting in Texas, disagree on the future of West Bank settlements under the Mideast peace plan. Both are under pressure.

CRAWFORD, Texas — President Bush and Israeli Prime Minister Ariel Sharon differed strongly and publicly Monday over the future of West Bank settlements under the U.S.-backed peace plan, underscoring the fragile nature of negotiations to end the decades-long conflict between Israel and the Palestinians.

Bush condemned the expansion of Jewish settlements as a violation of the so-called road map plan for a two-state solution. But Sharon, who has proposed expanding a major settlement east of Jerusalem, said the development and others would be protected under any final agreement and remain part of Israel. The two leaders spoke after meeting for an hour and a half at Bush's ranch outside Crawford.

"I told the prime minister of my concern that Israel not undertake any activity that contravenes road map obligations, or prejudice final status negotiations," Bush said after the meeting. "Therefore, Israel should remove unauthorized outposts and meet its road map obligations regarding settlements in the West Bank."

The impasse demonstrated that Bush and Sharon, despite a close alliance over the past four years, offer widely different interpretations of what the U.S.-supported peace plan means for settlements.

Backed by the United States, the European Union, Russia and the United Nations, the blueprint envisions a series of reciprocal steps by the two sides that would culminate in Palestinian statehood. The plan requires that Israel dismantle offshoots of Jewish settlements in the West Bank and that the Palestinian Authority crack down on militant groups.

Bush views the two-state plan as key to his broader agenda of promoting political reforms in the Middle East. But many analysts say he must challenge Sharon on the settlement expansion to keep the road map on track and to build credibility with Palestinians as an even-handed broker.

Sharon is under fire from many in his own right-leaning Likud Party for his plan to withdraw from the Gaza Strip. He is trying to mollify those critics by standing by the proposed expansion of a settlement east of Jerusalem called Maale Adumim.

The expansion, announced last month, has outraged Palestinians. They say it would cut off Palestinian areas in East Jerusalem from the West Bank, and significantly hinder north-south movement within the West Bank. Such a change, they say, would make it harder for Palestinians to build a free-standing state that is not carved into cantons by border crossings or tunnels.

Sharon refused Monday to concur with Bush's statement that the settlement's expansion violates the road map. Instead, the prime minister insisted that West Bank settlements would be protected throughout negotiations.

"It is the Israeli position that the major Israeli population centers will remain in Israel's hands under any future final status agreement with all related consequences," he said.

But as Bush and Sharon spoke Monday, it was clear the two men... have different visions about how to attain Middle East peace.

Both men offered some conciliatory language on other aspects of the plan.

Bush repeated the assurances given to Sharon in a letter a year ago that given the entrenched nature of many settlements, it was "unrealistic to expect that the outcome of final status negotiations will be a full and complete return to the armistice lines of 1949."

That language had given Israelis the expectation that they would be able to maintain some major West Bank settlements. Sharon pledged to "fulfill my commitment" to remove unauthorized outposts, often rusty trailers positioned by settlers on bare West Bank hilltops.

But as Bush and Sharon spoke Monday, it was clear the two men — while reiterating their friendship and mutual interest in ranching — have different visions about how to attain Middle East peace.

Sharon, directing his remarks to television viewers back home, said in Hebrew that his Gaza pullout was the first step toward an end to the dispute with Palestinians, but that further steps under the road map would be possible only after the Palestinians eliminated violence.

"I hope that this stage will happen and that we will only move to the road map after this intervention by the Palestinians against terror," he said.

Sharon strongly promoted his Gaza withdrawal initiative, calling on the Palestinians to help and declaring it would "strengthen Israel, improve the quality of life for Israeli citizens, reduce the friction between us and the Palestinians and can pave the way towards the implementation of the road map."

Bush linked the road map to Israel's withdrawal from Gaza, making it clear that he hoped the pullout would build momentum for the peace plan. But Sharon took pains to portray the peace plan as a long-term approach, reflecting Israeli skepticism about the plan. He said a successful Gaza withdrawal by Israel, with the cooperation of the Palestinian Authority, would build confidence on both sides and clear the way for two states.

"I want to focus the world's attention on getting it right in the Gaza, and then all of a sudden, people will start to say, 'Gosh, well, that makes sense,' " Bush said. "The Palestinians will see it's a hopeful — there's a hopeful way forward."

Independent analysts argued that Bush needed to establish his differences with Sharon on the settlements issue to protect the road map.

"If Bush truly wants to be remembered as the man who finally brokered a deal between the Israelis and the Palestinians, then the West Bank has to be next," said Geoffrey Kemp, a Middle East specialist at the Nixon Center, a Washington think tank.

"It's important that Bush lay down this marker now because the turmoil in Israel will get much worse in the coming months — first, because the actual withdrawal from Gaza will be very public and very painful, but also because for the huge lobby in favor of settlements, it's an ominous sign that they will be next."

Both men face political risks at home as they seek to implement the peace plan.

Bush, who capitalized on his hard-line stance against the late Palestinian leader Yasser Arafat to woo votes last year from conservative Christians and Jews, is now facing criticism from among those groups for moving too fast with the Palestinians.

Bush's 2004 letter to Sharon on settlements reassured Israel backers in the U.S. that the president was sympathetic to settlers who might get left outside the Jewish state's borders under a two-nation plan. Unencumbered by reelection concerns, Bush and his administration have insisted that Israel follow the road map's admonition to halt settlement expansion in the West Bank.

"If he listens to what I say, he won't hear anything contradictory," Bush said testily after a reporter asked about mixed signals on settlements. "I've been very clear about, Israel has an obligation under the road map. That's no expansion of settlements."

For Sharon, the settlement debate, and the pressure that Bush decides to apply, is fraught with political peril.

Although Sharon pledged Monday to remove unauthorized West Bank outposts, he has found it politically difficult to follow through on such commitments, because they usually entail Israeli military forces confronting settlers in emotional, ugly scenes.

Television coverage of such events further inflames the emotions of right-wing Israelis already upset by Sharon's Gaza pullout plan and limits his political maneuverability.