The string of walls, razor wire, ditches and fences has enflamed already high tensions between Palestinians and Israelis. The United States has criticized the barrier's planned route deep into the West Bank, saying it could harm efforts to set up a Palestinian state.
Israel has said the barrier is meant to keep out Palestinian militants responsible for the deaths of hundreds of Israelis in the past three years of violence. But Israeli Prime Minister Ariel Sharon said Tuesday it will also prevent tens of thousands of Palestinians from moving into Israel — as officials say has occurred in recent years.
Palestinians say the snaking barricade is an Israeli attempt to seize West Bank land Palestinians claim for a future state.
About 90 miles of the barrier has been completed around the northern West Bank, mainly following the invisible boundary with Israel.
The unbuilt southern section, almost 430 miles long, will cut up to 14 miles into the West Bank, according to the U.N. Office for the Coordination of Humanitarian Affairs. This seems aimed at incorporating some Jewish settlements into the "Israeli" side.
The barrier will carve off 14.5 percent of the West Bank, affecting roughly 680,000 people, nearly one-third of the Palestinians living in the West Bank, the report said.
"People's lives will be seriously disrupted," said David Shearer, head of the local UNOCHA office. The barrier will be "disastrous" for farmers, who will find it difficult to get to their fields and bring their produce to market, he said.
"For economic reasons, for education reasons, people will find it impossible to stay in these areas, and they will choose to move out," Shearer said.
Palestinian officials, meanwhile, prepared for a vote of confidence Wednesday on the new Cabinet of Prime Minister Ahmed Qureia.
U.S. and Israeli officials have expressed reservations that the Cabinet leaves Palestinian leader Yasser Arafat with a firm grip over security forces.
Even so, Sharon has said he is ready to meet with Qureia. Palestinian Cabinet secretary Hassan Abu Libdeh said U.S. officials told him they would also reserve judgment.
"The Americans were not content with the formation of the government, but they said they would judge the government by its performance, by its actions," Abu Libdeh said.
Palestinian officials say they have been pressing militant groups to end attacks on Israel so talks can resume on implementing the U.S.-backed "road map" peace plan, which calls for a Palestinian state by 2005.
Palestinians need an "open-ended cease-fire ... that must be reciprocated by the Israelis," Palestinian Foreign Minister Nabil Shaath said.
Israel is not ruling out a cease-fire but it must be backed by action to crack down on terrorist organizations, a senior Israeli official said, insisting on anonymity. Qureia has said he will not use force against the militants.
Palestinian officials said they remained concerned about scores of unauthorized Israeli settlement outposts throughout the West Bank. The plan calls for a complete Israeli settlement freeze, which Sharon has so far refused to order.
Israeli Defense Minister Shaul Mofaz said defense officials would continue to evaluate the outposts along with Israel's security needs.
"I have to say that in the past year, a number of outposts were dismantled," most of them in agreement with settlers, Mofaz told Israeli Army Radio on Tuesday after meeting with Defense Secretary Donald Rumsfeld in Washington.
Peace Now, an Israeli monitoring group, said the number of outposts has dropped slightly since the road map was unveiled in June, to 101 or 102. But Peace Now expert Dror Etkes said the population and infrastructure have grown.
Mofaz said the security barrier did not come up in his talks with Rumsfeld.
Asked about concerns the United States may withhold some aid to Israel because of the fence, Mofaz said: "I don't know yet if there will be a price as far as U.S. aid is concerned. It will certainly be discussed in the future."
"But to the question of need, I have no doubt that this is necessary, and I can explain this to the Americans."
Palestinian officials have strongly condemned the wall's route.
"Palestinians see the continuation of the wall as burying the hope for peace and killing the vision of a two-state solution," Palestinian Cabinet Minister Saeb Erekat said. "It's really a disaster ... a human catastrophe in the fullest extent of the word."
Israeli officials say the barrier has reduced the number of infiltrations in areas where it has been completed.
The barrier has gates, intended to give farmers access to their fields, Deputy Defense Minister Zeev Boim told Israel Radio.
Human rights groups say the gates are often closed.