The Israeli government is trying a new tactic in its war against terror — instead of quick in-and-out raids to capture militants, or selective assassination of militia leaders, the Israeli military plans to simply occupy Palestinian Authority land until the waves of homicide bombings completely stop. 

In Washington, White House spokesman Ari Fleischer said: "The president understands Israel's right to self-defense, particularly in the wake of an attack of this severity." 

U.S. officials said afterward, however, that Fleischer's remarks were not intended to be an endorsement of Israel's actions but rather an acknowledgment of the pressure on Prime Minister Ariel Sharon to act. 

The new Israeli approach in effect redraws the map of the West Bank and undermines Arafat's weakened government even further — and also undermines President Bush's peace plan, which considers a reformed and strengthened Palestinian state essential to ending Islamic militant terror. 

Administration officials said that Bush's speech announcing his plan would be delayed until later this week or the beginning of next week. 

The newly announced Israeli policy went into effect Tuesday night, with tanks and infantry moving into the northern West Bank town of Jenin and the adjacent refugee camp, scene of fierce fighting earlier this spring. 

Troops were seen preparing for an extended stay, installing mobile homes and water tanks brought in on flatbed trucks. 

Tuesday's Jerusalem bus blast that killed 19 people was given as the immediate reason for the Israeli tactical shift, but such a major undertaking must have been considered for some time beforehand. 

Although the Islamic militant group Hamas claimed responsibility for the homicide bombing, the Israeli government maintains that Palestinian Authority leader Yasser Arafat is ultimately responsible for failing to curb the terror attacks. 

In one of his strongest condemnations ever, Pope John Paul II decried the bombing, saying "those who plot and plan such barbarous attacks will have to answer before God." 

A U.S. official said Wednesday in Washington that Bush planned to propose establishing a Palestinian state with provisional boundaries, but only after extensive Palestinian reforms that could take up to a year to implement. 

A timetable for negotiating permanent borders also could be included, perhaps mentioning a soft date three years off for those decisions to be made if progress was deemed satisfactory. 

Bush, the official said, also planned to ask Israel to end settlement expansion in Palestinian areas and call again for a peace conference focused on Palestinian security measures. 

Sharon adamantly opposes any sort of Palestinian state being established while violence continues, so such a proposal from Bush could be acceptable to Israel. 

"It is interesting to know what kind of Palestinian state they mean," Sharon angrily asked of the Americans after he toured the scene of Tuesday's suicide bombing. 

Israeli Foreign Ministry spokesman Gideon Meir refused to comment on the report ahead of Bush's speech. 

Palestinian Information Minister Yasser Abed Rabbo wouldn't comment on specifics of the plan before it is revealed, but reiterated that the Palestinians want a final state, not an interim solution. 

Arafat adviser Ahmed Abdel Rahman warned the new Israeli policy would cause only more violence. 

"The occupation will not ensure Israel's security, but will escalate and complicate the situation more and more and push the Palestinians to resist harder," Abdel Rahman said. 

Just how far Israel would go in retaking Palestinian territory wasn't clear. Before the Palestinians were granted full or partial authority over areas through the interim peace accords of the mid-1990s, Israel oversaw all aspects of daily life. Soldiers patrolled all towns, cities and villages, frequently imposing curfews that could close schools and offices for days or weeks. 

Palestinian Cabinet minister Saeb Erekat accused Sharon of following a secret agenda of replacing the Palestinian Authority with full Israeli rule. 

Jibril Rajoub, the Palestinians' West Bank security chief, said the Palestinians cannot cooperate with Israel now to arrest those behind suicide attacks. 

"As long as the Israelis are continuing their invasion — using their tanks, F-16s and Apaches [attack helicopters] — there will be no arrests of any Palestinian," Rajoub told The Associated Press from Egypt, where he was meeting with officials about Palestinian security matters. 

However, several dozen prominent Palestinians, led by legislator Hanan Ashrawi and the Palestinians' senior Jerusalem official, Sari Nusseibeh, signed a full-page newspaper ad urging groups behind deadly assaults on Israeli civilians to "stop sending our young people to carry out such attacks." 

"We see no results in such attacks, but a deepening of the hatred between both peoples and a deepening of the gap between us," the ad in Al Quds newspaper said. It urged all Palestinians who support such a call to sign on to it. 

Jenin residents said Israeli troops set up mobile homes just west of the town, took over a school in the refugee camp, forcing open doors with sledgehammers, and searched five apartment buildings. About 30 camp residents were detained, witnesses said. 

The Israeli military said troops took over commanding positions in the town, declared a curfew and arrested four suspects. They blasted their way into the administrative offices of Al Razi hospital, run by an Islamic charity affiliated with Hamas, and blew up a safe, according to hospital director Ali Jabareen. 

A few hours later, Israeli troops briefly raided the West Bank city of Nablus and arrested three suspects. Troops also entered Qalqiliya, just inside the West Bank, declared a curfew and searched for suspects, the military said. 

In Ramallah, where Arafat has his headquarters, residents were hoarding food and expecting an Israeli onslaught. Israel has frequently encircled or entered Arafat's city-block-sized headquarters there after Palestinian homicide bombings. 

The Israeli decision for long-term reoccupation came after late-night consultations between Prime Minister Ariel Sharon and his coalition partners. 

"Israel will respond to acts of terror by capturing Palestinian Authority territory," Sharon's office announced. "These areas will be held as long as terror continues. Additional acts of terror will lead to the taking of additional areas." 

Right-wing members of the Israeli government long have demanded Israel retake all areas handed to the Palestinians under interim peace accords in the mid-1990s, but the moderate Labor Party has resisted such a step. 

Sharon told Cabinet ministers Tuesday that although he favored Arafat's expulsion, he would not override Defense Minister Binyamin Ben-Eliezer and the security chiefs who oppose such a step as counterproductive, Israeli media said. 

Israel Radio reported Wednesday that security officials also were considering expelling Arafat aides. 

Israeli government spokesman Arieh Mekel said the new policy was intended to jolt Arafat into finally taking action against terror groups. Asked whether Israel is moving to dismantle the Palestinian Authority, he said that "hopefully, we won't get to this stage." 

If Arafat does not understand the warning and there are more attacks, however, "we will take more and more of it [Palestinian areas] and it will lead to wherever it may lead," Mekel said. 

The Associated Press contributed to this report.