Army mapmakers presented new options Tuesday for Israel's West Bank barrier, moving it closer to Israel and aiming to minimize hardships for Palestinians.

The world court has denounced the barrier; the government said it was responding to an Israeli court order.

Also Tuesday, the opposition Labor Party approved formal talks to join Prime Minister Ariel Sharon's (search) government, a party official said. Such an alliance would strongly boost chances of Sharon's Gaza withdrawal plan (search). Sharon lost his parliamentary majority over the pullout proposal.

Early Wednesday, Israeli helicopters fired missiles at a metal workshop in Gaza City, sparking a fire and sending plumes of black smoke over the town, residents said. No casualties were reported.

The Israeli military said the building contained several workshops where Hamas and other militant groups made rockets, which are often fired at Jewish settlements in Gaza and Israeli towns just outside the territory.

The military put forth options for changing the West Bank barrier route in a meeting between U.S. envoys Elliot Abrams and Steve Hadley and Israeli Defense Minister Shaul Mofaz (search), officials said.

Two weeks ago, Israel's Supreme Court said the separation barrier could be built to keep out Palestinian attackers, but its planned path violates international law and should be redrawn to ease the lives of Palestinians.

"We're looking at ways to bring the fence closer to the Green Line," Foreign Ministry official Gideon Meir said, referring to Israel's pre-1967 Mideast War frontier with the West Bank.

The barrier is about one-quarter completed, and Israel says it already has contributed to a reduction in Palestinian attacks. During four years of conflict, hundreds of Israelis have been killed in bombings by Palestinians who infiltrated from the West Bank.

Last week, the International Court of Justice issued a nonbinding ruling declaring the barrier illegal and saying it must be dismantled.

Israel rejected the ruling. Sharon said Israel would continue to build the planned 425-mile complex of concrete walls, wire fences and trenches.

"What counts is the decision of the Supreme Court of the state of Israel," Meir said.

Hassan Abu Libdeh, the Palestinian Cabinet secretary, said Israel must build the barrier entirely on its territory, and that any changes falling short of that are unacceptable.

Palestinians say the planned route, which in places dips deep into the West Bank, amounts to a land grab.

In its ruling, the Israeli high court said the barrier should not run next to Palestinian villages or separate Palestinians from their fields and schools.

Tzvika Bar-Chai, a Jewish settler leader in the southern West Bank, said he was informed that some nine settlements in the area, to have been included on the "Israeli" side, will now be outside the barrier.

Labor favors giving up most of the Palestinian territories in exchange for peace and strongly backs Sharon's plan to pull out of Gaza.

Meeting in Tel Aviv on Tuesday, the Labor Party leadership authorized representatives to negotiate with Sharon's Likud toward joining the government coalition. Avraham Shochat, a party leader, said a large majority voted in favor of the move after chairman Shimon Peres said Labor would demand a timetable for the Gaza withdrawal and domestic economic reforms.

However, there is opposition in both parties to a joint government. Hard-liners in Likud, who oppose the Gaza pullout, are against Labor's joining the government to boost the plan.

Labor critics say the party should be working to bring down the government and force elections instead of joining up with Sharon again. Labor served in Sharon's government for more than a year, pulling out in late 2002 in a dispute over funding for Jewish settlements.

At the Tel Aviv meeting, Peres responded to critics who charged that Sharon was using Labor to maintain his hold on the premiership.

"They say we're being used," he said. "What are they using us for? To bring peace? Should we be embarrassed by that?"

Sharon met Tuesday with Abrams and Hadley. The prime minister told them Israel would fulfill its obligations, including dismantling dozens of unauthorized outposts in Palestinian areas under the internationally backed "road map" peace plan. Israeli officials, speaking on condition of anonymity, said the envoys pressed for quicker action.

The U.S. envoys met Monday with Palestinian Prime Minister Ahmed Qureia. They return to Washington on Wednesday.

Also Tuesday, Israeli troops killed a Palestinian militant in the West Bank during a car chase in the Jenin refugee camp, and three militants from the Islamic Jihad were arrested there, the military said.