Prime Minister Ariel Sharon faced stiff opposition as he promised to seek parliamentary approval and consult with the United States before imposing what he calls a temporary boundary on the Palestinians.

Meanwhile, Israeli troops in the West Bank conducted house-to-house searches in theTulkarem (search) refugee camp for a second day Tuesday, and Palestinian witnesses said about 200 residents were rounded up for questioning.

The Israeli military said it arrested six suspects, including one man allegedly planning to carry out a suicide bombing in Israel.

Sharon reiterated Monday that he remains committed to the U.S.-led "road map" plan that envisions a peace deal by 2005, with a Palestinian state as a centerpiece.

But during a heated session of the Knesset (search), Sharon said Israel would move unilaterally if it becomes apparent "within a few months" that the Palestinians are not meeting their obligations — especially dismantling militant groups. Both sides so far have failed to move forward on the peace plan.

"I will of course bring the steps that the government decides on .... to the Knesset for approval, so that we can hold a serious and comprehensive debate on the subject," Sharon said.

Meanwhile, Sharon's top deputy, Ehud Olmert (search), set a timetable for the first time, saying a partial withdrawal from the West Bank and Gaza Strip and the dismantling of some Israeli settlements could begin within six months.

But parliamentary approval is not guaranteed.

Sharon's hard-line allies complain he has abandoned his pro-settlement philosophy. The moderate opposition would welcome the dismantling of settlements, but suspects Sharon is trying to turn what he bills as a temporary solution into a nonviable permanent one — the creation of a Palestinian state in only about half the West Bank.

Sharon, in a speech punctuated by catcalls from all sides, did not refer to the possible dismantling of settlements, apparently to avoid further angering his political allies. On Sunday, leading members of his Likud Party joined settler leaders and tens of thousands of their supporters in a protest rally against a possible pullback.

Sharon also said Monday he would consult with the United States before making a final decision. Washington has said the conflict could be solved only by a negotiated solution.

The Palestinians are increasingly worried about Sharon's plan.

Chief Palestinian negotiator Saeb Erekat said Monday that Israel may be able to impose a boundary but "will not have a partner on the Palestinian side."

Erekat said the Palestinians remain committed to a two-state solution — with a future Palestine made up of the West Bank, Gaza Strip and east Jerusalem, lands Israel captured in the 1967 Mideast war — but that an agreed partition may become impossible if Sharon forges ahead with his plan.

In the parliament, dovish opponents charged that Sharon's real intention was to torpedo peace efforts.

Dalia Itzik of the moderate Labor Party said Sharon's government "has become the rejectionist government of the region — no to peace, no to recognition, no to negotiations," parodying a 1969 Arab League pronouncement rejecting contact with Israel.

However, Sharon seemed ready to move.

He told parliament he has asked his incoming national security adviser, Maj. Gen. Giora Eiland, to oversee preparations for unilateral steps. Eiland reportedly is already in touch with government ministries to coordinate a partial withdrawal.

Israel is building a separation barrier in the West Bank, saying the network of trenches, fences and cinderblocks is necessary to keep out Palestinian militants who have killed hundreds of Israelis in shootings and bombings the past three years.

Sharon has indicated that the barrier, denounced as an "apartheid wall" by the Palestinians, would form the boundary under his plan. The barrier will dip deep into the West Bank in several places and encircle villages and towns, cutting tens of thousands of Palestinians off from their farmland and vital services.

As part of the barrier system, Israeli construction crews Monday erected 26-foot-high concrete slabs in Abu Dis, a West Bank suburb of Jerusalem. The massive wall replaced a lower barrier that had slowed, but not stopped, the flow of people and goods between Jerusalem and the West Bank. The new construction suggested that Israel's encirclement of Jerusalem is becoming more permanent.

Parts of the barrier have been put up elsewhere around east Jerusalem but the section erected in Abu Dis is the most intrusive yet.