Prime Minister Ariel Sharon (search) presented a sweeping defense of his plan to remove Israeli troops and settlers from the Gaza Strip (search) and parts of the West Bank (search), saying he has to fend off increasing international pressure, protect Israel and prevent a Palestinian humanitarian disaster.

Sharon announced earlier this week that he would hold a binding referendum among 200,000 Likud Party members on the withdrawal plan. The party is divided over the proposal, with several senior Likud figures opposing it. Initial polls suggest a pullback would win narrow approval.

"Remaining in the current situation is dangerous for Israel," Sharon told a technology conference Wednesday night, in what was seen as the start of his campaign to win support for the plan among members of the party.

In his speech, Sharon warned that the status quo is untenable. "The world will not allow a deadlock to continue. A deadlock will bring sooner or later proposals that are dangerous for Israel," he said.

Details of his "disengagement plan" are still being worked out in discussions with the United States. The government has discussed removing troops and settlers from most or all of Gaza and some areas of the West Bank if peace talks remain frozen.

Sharon said Israel must draw its own security line, which would mean withdrawing from areas that wouldn't be under Israeli control in a final agreement with the Palestinians. He said that included the Gaza Strip.

A team of U.S. envoys was making its third visit to the region since February to discuss details of Sharon's plan. Sharon is to meet President Bush in Washington on April 14 to discuss it further.

The U.S. envoys began talks in the West Bank town of Jericho on Thursday with Palestinian Prime Minister Ahmed Qureia (search). Qureia has said he welcomes an Israeli withdrawal from any territory, but only as a first step to a full withdrawal from Gaza and the West Bank.

Later Thursday, they were to head to Jerusalem to meet with Sharon.

In his speech Wednesday, Sharon, a hard-liner who was one of the main champions of settlement, gave some insight into what made him change his mind.

Sharon said he had high hopes for the U.S.-backed "road map" peace plan when it was unveiled last year, but soon felt the Palestinians were not serious about the plan, particularly a requirement that they crack down on militants. For its part, Israel did not meet its requirement to dismantle dozens of settlement outposts.

"As soon as we saw that there is not a Palestinian partner we moved on to a totally different situation, there's no possibility of reaching an agreement and Israel must act alone," he said.

Sharon said he proposed his "disengagement plan," because the other options — to annex the West Bank and Gaza, to completely pull out of the areas or to do nothing — would be disastrous for Israel.

Annexing the territory would force Israel to kick out the Palestinian Authority and take responsibility for the daily lives of Palestinians, he said. A complete withdrawal would be a "security disaster," he said.

Maintaining the status quo would be dangerous as well, because international donors, who provide the majority of funding for the Palestinian Authority, are reluctant to keep giving money amid the continuing violence and Israeli travel restrictions that damage the Palestinian economy, he said.

"This situation will bring a humanitarian collapse and the pointing of an accusatory finger at Israel," he said.

The "disengagement plan" will lower friction between the Israelis and Palestinians and allow it to diffuse increasing diplomatic pressure, he said.

"Israel must take a step that will prevent political collapse," Sharon said.

Palestinians want a state in all the West Bank and Gaza. But many in Sharon's hardline government view his limited withdrawal plan as the most they are willing to concede.

Also Thursday, a shootout erupted at a mental hospital in the West Bank town of Bethlehem when soldiers and Palestinian militants holed up in the building traded fire. Twelve wanted Palestinians later surrendered the army said. No one was injured.

The suspects are members of the Al Aqsa Brigades militia and former officers with Palestinian security services, the army said.

Elsewhere in the West Bank, Israeli police clashed with Jewish settlers who were trying to rebuild an unauthorized outpost near Hebron that the army took down Wednesday. Police spokesman Gil Kleiman said 14 settlers were arrested and charged with entering a closed military area they tried to construct a stone wall.

Israel is supposed to remove dozens of unauthorized outposts under the road map, but has taken little action against the outposts.