Secretary of State Colin Powell said Wednesday he would push ahead with his peacekeeping mission in the Middle East despite Israel's objections to his meeting Palestinian leader Yasser Arafat. An Israeli military withdrawal from three West Bank towns drew support from the White House.

"The withdrawal the president has called for is continuing. Now the Palestinian Authority and Arab nations have to do what the president called for," White House spokesman Ari Fleischer said in Washington. The statement did not mention Arafat by name.

"The burden isn't Israel's alone. All parties have responsibilities," Fleischer said on the eve of Powell's visit to Israel.

Israel's defense ministry had announced that Israeli troops were leaving the Palestinian villages of Yatta, Qabatya and Samua.

The White House statement was a shift from the administration's objections earlier Wednesday over Israel's slowness in meeting Bush's demands for a withdrawal.

In his earlier remarks, Powell brushed aside Sharon's assertion that the secretary's planned meeting with Arafat this weekend would be "a tragic mistake." Powell said his mission was "not in the least in jeopardy."

He said he hoped Sharon would help the meeting take place and ease restrictions on Arafat in Ramallah to help him communicate more readily with other Palestinian leaders.

"He is the partner that Israel will have to deal with," Powell said after his peace mission was endorsed in Madrid by the European Union, the United Nations and Russian Foreign Minister Igor Ivanov.

America has pressured Israel to pull troops out of West Bank cities and end its 13-day offensive. Despite the newly announced withdrawals, Israeli troops still occupy the major population centers of Ramallah, Nablus, Jenin and Bethlehem.

Powell is trying to persuade Sharon to pull his troops back entirely, Arafat to speak out against terror and for both sides to return to the negotiating table.

The crux of Powell's two-step plan is to try to arrange a cease-fire between Israel and the Palestinians and then steer them into negotiations that would culminate in a Palestinian state on land Israel now holds.

But Sharon pledged on Wednesday to maintain the offensive until Palestinian militias are destroyed.

Even if Powell gains a cease-fire, many in the region question how well it might hold if there are more Palestinian suicide attacks. Further, mistrust would make talks about future borders and a Palestinian state difficult, with the constant threat of a wider war in the region.

As he trekked through the Middle East and then detoured to Spain, Powell made plain that his other objectives include renewing security cooperation between Israel and the Palestinians, asking Saudi Arabia for assistance to rebuild Palestinian facilities and organizing a worldwide relief effort for Palestinians.

"We understand the difficult situation that Israel finds itself in, but we believe that the best way to relieve this tension, the best way to move forward and provide a solution to the crisis that we find ourselves in, is for the withdrawal of Israeli forces," Powell said at a news conference.

Powell is due in Israel late Thursday after a stop in Jordan to talk to King Abdullah II. He is to see Sharon in Jerusalem on Friday and hopes to see Arafat on Saturday.

President Bush, after first strongly supporting the Israeli leader, last week demanded that Sharon call a halt. As a result, U.S. policy is now more in line with the views of Arab and European governments.

Sharon, on the other hand, feeling the continuing sting of Palestinian suicide attacks on Israelis, told reporters while touring an Israeli army base near the West Bank refugee camp of Jenin that he had informed Bush he could not pull troops back immediately.

"Here we are in the middle of a battle," Sharon said. "If we leave, we will have to return. Once we finish, we are not going to stay here. But first we have to accomplish our mission."

In Washington, White House spokesman Fleischer reiterated that he wants the Palestinian Authority and Arab nations to "publicly denounce terrorism, stop funding it, stop inciting violence in state-owned media and begin to implement" peace process plans. In a break from past practice, the statement did not ask Israel to pull back its troops.

The leaders in Madrid urged both Israelis and Palestinians to cooperate with Powell.

"There is no military solution to the conflict," said a joint statement issued by four leaders and Powell. The statement called for an immediate cease-fire and Israel's withdrawal from Palestinian-held cities on the West Bank, including Ramallah, where Arafat is confined.

At the same time, the officials said, "Terrorism, including suicide bombing, is illegal and immoral."

Meanwhile, in advance of Powell's visit, U.S. envoy Gen. Anthony Zinni met with Palestinian officials in Jerusalem.

And Vice President Dick Cheney spoke with Syrian President Bashar Assad and made clear Bush's admonition to stay out of the Israeli-Palestinian conflict, a State Department official said. He said Cheney also stressed the need to act and speak against terrorism and violence.

The official, asking not to be identified, noted that the United States has condemned recent attacks on Israel from Lebanese territory and attempts by any party to escalate the conflict through military action.

U.N. Secretary-General Kofi Annan said Syrian and Lebanese leaders had assured him they would try to curb the guerrilla attacks on Israel from Lebanon.

A senior U.S. official called the situation serious and said Israel was being urged to act with restraint in response to Hezbollah attacks.