With peace hopes dashed after three weekend suicide bombings that killed 26 Israelis and injured 200 more, White House officials say it's important for Israel and Palestinian leader Yasser Arafat to continue their dialogue — a diplomatic way of calling on Israel not to target Arafat personally for attack.

On Monday, Israel retaliated by bombing Arafat's helicopter pad in Gaza City, destroying two helicopters. Arafat was in the city of Ramallah at the time.

White House spokesman Ari Fleischer gave the impression Monday that the White House was okay with Israel's decision to retaliate.

"Obviously, Israel has a right to defend herself and the president understands that clearly," Fleischer said.

President Bush said the weekend attacks were clearly aimed at derailing Middle East peace efforts and were timed just as the most intense negotiating effort of his administration was getting under way.

Bush had sent retired Marine General Anthony Zinni to the region to try and arrange a cease-fire. Zinni, who has been in Israel for just a week, was scheduled to have meetings this week. He said those meetings will go on.

Bush had also been planning to use a visit this week with Israeli Prime Minister Ariel Sharon to shift some of his focus from the war in Afghanistan to the Middle East.

The attacks, however, shifted the focus ahead of Bush's timetable, and the president met with Sharon in the White House Sunday, a day earlier than planned, so that Sharon could head back to Israel for an emergency Cabinet meeting.

During the meeting, Sharon told the president point blank that Arafat was personally responsible for the attacks, according to Israel officials. Officials gave no indication that Bush had sought to persuade Sharon to hold back in his response to the attacks.

Arafat "must do everything in his power to find those who murdered innocent Israelis and bring them to justice," Bush said.

Bush has scheduled meetings with other leaders central to the peace process for later in the week.

Following the attack, he urged other Arab leaders in the area to take a more active role in bringing about stability and peace. "The advocates of peace in the Middle East must rise up and fight terror," he said.

However, Hassan Abdel Rahman, the Palestine Liberation Organization's chief representative in the United States, said the Palestinian Authority was trying its best to control violence.

"But in order for them to succeed they need reciprocal steps from Israel," Rahman said in an interview.

For instance, he said, Israel should stop its policy of assassinating Palestinian community leaders, lift its siege of the West Bank and Gaza and stop demolishing the homes of Palestinians.

But Bush and his aides are not satisfied with that response and have called on Arafat to prove his commitment to fight terror by exercising what power he has over Hamas and other terrorist groups.

"This is a real opportunity for Arafat to show, in action not words, that he stands for peace," Fleischer said.

Bush said Arafat must act swiftly and decisively.

"We must not allow terror to destroy the chance of peace in the Middle East. Now is the time for leaders throughout the world who urge there to be a peace to do something about the terror that prevents peace from happening in the first place."

Since entering the White House, Bush has not met with Arafat, saying he must make efforts to secure the peace before such a meeting can take place. Bush has never said precisely what Arafat must do — beyond exercising 100 percent of his ability to rein in terrorism and end violence. That violence includes not just suicide bombings but the "intifada," the uprising that includes day-to-day rock throwing.

White House officials say the president expects Arafat to break up Hamas and Palestinian Islamic Jihad despite the fact that those groups are as popular as Arafat among many Palestinians.

So far, Arafat's police force has arrested 100 people. Secretary of State Colin Powell said they must be put in real jails, where they're not walking free several days later.

After speaking with Arafat by telephone, Powell said he had made "absolutely clear that these despicable and cowardly actions must be brought to an end through immediate, comprehensive and sustained action by the Palestinian Authority."

Pentagon officials said they are not surprised by Israel's response to the attacks, and have not been asked for help. Officials said they are not holding out hope that this is the last round of attacks and responses.

On Sunday, Defense Secretary Donald H. Rumsfeld suggested Arafat may not have a sure grip on the Palestinian movement.

"He is not a particularly strong leader. And I don't know that he has good control over the Palestinian situation," he said.

Fox News' Wendell Goler and the Associated Press contributed to this report.