Israel's plans to build hundreds of new homes in Jewish West Bank settlements have put Prime Minister Benjamin Netanyahu at odds again with Washington and the Palestinians, without appeasing settlers furious over the government's plan to dismantle an illegally built enclave.

Engineers, meanwhile, questioned the government's plan to physically uproot the five apartment buildings that make up the Ulpana enclave, saying it would be a colossal waste of money and likely doomed to fail. Netanyahu, an ardent settlement champion, has proposed that plan to avert the spectacle of settlement homes being demolished on his watch.

On Wednesday, officials announced the government would build 850 apartments in various West Bank settlements. This came after parliament, at Netanyahu's urging, voted down a bill that would have legalized Ulpana and other settler outposts built illegally on privately held Palestinian land.

The international community condemns settlement construction, and the Palestinians have refused to talk peace while Israel builds on land they claim for a future state.

Netanyahu found himself in the politically difficult position of having to carry out a Supreme Court ruling ordering the 30 apartments in Ulpana destroyed by July 1. Knowing proposed legislation to preserve the outpost would not stand up to the court's scrutiny, he pressured coalition lawmakers to vote it down on Wednesday.

To blunt the blow to settlers, he vowed to build 300 more homes in the authorized settlement of Beit El, on whose outskirts Ulpana lies.

Later, Housing Minister Ariel Attias announced that an additional 551 apartments would be built elsewhere in the West Bank.

"Thirty apartments will be evacuated, but 850 will be built instead," Attias said in a statement. "Under the circumstances, this is a worthy solution."

The Palestinians and Washington disagreed.

Senior Palestinian official Saeb Erekat denounced the new construction as a measure "that undermines all efforts to revive the peacemaking between the two sides."

Settlement construction is at the heart of the current impasse in peace talks. Negotiations broke down three years ago, and the Palestinians refuse to restart negotiations until Israel freezes settlement construction in the West Bank and east Jerusalem.

With 500,000 Israelis now living on land claimed by the Palestinians, they say their dream of gaining independence is growing ever more distant. Israel says negotiations must be conducted without preconditions.

In a sharply worded statement, the U.S. accused Israel of hindering peace efforts with the newly announced settlement construction — and appeared to question both sides' declared commitments to peacemaking.

"We're very clear that continued Israeli settlement activity in the West Bank undermines peace efforts," U.S. State Department spokesman Mark Toner said. "We do not accept the legitimacy of continued Israeli settlement activity."

He did not say what, if any, response the U.S. would take. In an election year, President Barack Obama would be unlikely to pick a fight with Israel, which enjoys significant support among Jewish and evangelical Christians.

The U.N. envoy to the Middle East, Robert Serry, called the planned new construction "deeply troubling" and "contrary to international law." He urged both Israelis and Palestinians to work for a solution.

"If the parties do not grasp the current opportunity, they should realize the implication is not merely slowing progress toward a two-state solution," he said. "Instead, we could be moving down the path toward a one-state reality, which would also move us further away from regional peace."

Israel would lose its Jewish majority in such a state, which would incorporate the West Bank, Gaza Strip and east Jerusalem, territories Israel captured in the 1967 war.

Settlers, meanwhile, vowed to resist the impending evacuation, though they stopped short of threatening violence.

Ulpana resident Reut Lehrer told Army Radio on Thursday that "there was a lot of anger" there at the government following the parliament vote. "People feel we have been abandoned," she said.

On Wednesday evening, shortly after the parliament vote, police used stun guns to disperse a group of about 40 settlers who were throwing rocks at Palestinian cars, police spokesman Micky Rosenfeld said.

The violence raised fears of further attacks on Palestinians and their property, a tactic known as "price tag" that extremist Jews use to vent their anger at government action against settlers.

Government officials, meanwhile, were working on Netanyahu's unprecedented promise to physically uproot settler houses and move them intact to a site about one kilometer (half a mile) away. The project would begin after the 150 Ulpana settlers are moved into state-funded mobile homes, pending the relocation of their homes.

Israel David, vice chairman of the Israeli Association of Construction and infrastructure Engineers, estimates the project would cost anywhere from $13 million to $25 million — and in the end fail.

"I don't think it's feasible, because of the topography and the type of construction,' he said of the buildings, which each house six apartments and are located on hilly ground. He said it was possible the structures would crumble while being transferred — just the scenario Netanyahu hopes to avoid.

Asked why he thought the government would undertake a project he professionally views as so quixotic, David replied: "It's a good spin. No one did their homework on this."