Amman, Jordan ? Secretary of State Colin Powell told Israel on Thursday that its military operations against Palestinians on the West Bank would not eliminate the threat of terror. The White House declined to criticize the pace of Israel’s limited pullback.

Powell said frustrations will remain among the Palestinian people that could only be addressed in negotiations.

Powell said he spoke with Israeli Prime Minister Ariel Sharon while in Madrid to map out the meeting they will hold in Jerusalem on Friday.

Asked whether he was on an impossible mission, Powell snapped: “I don’t like wallowing with pessimists. It is necessary for me to go.”

“I am proud to be going, I am pleased to be going … to get the sides back on track,” he said. “My mission is still on. I’m not concerned about it.”

Powell was scheduled to arrive in Jerusalem late Thursday.

On his way, the secretary of state stopped in Jordan to talk over dinner with King Abdullah II at the monarch’s palace, known as Beit al-Barakeh, Arabic for the House of Blessing.

He told the king the length of his stay in the region depended on how he fares on “what has to be done and what must be done.”.

In a picture-taking session before dinner, Abdullah said “you know that we are so worried that if you fail,” but did not complete the sentence.

Earlier in the day, Powell said he talked with Sharon via phone about Israeli withdrawals from two towns and 22 villages and said he would have a better idea of Sharon’s long-term objectives after their meeting.

“However long the Israeli incursion continues, the problems will still be there,” he said. Even if Israel is effective, “There will still be people willing to resort to violence and suicide bombings. … The violence and anger and frustration which feeds that will still be there unless we find a negotiating process” that leads to a Palestinian state.

In Washington, White House spokesman Ari Fleischer took note of the limited withdrawals and raised no objection to the pace of Israel’s response to President Bush’s pleas.

“The withdrawals he called for are continuing,” Fleischer said, reiterating that Bush also wants Palestinian leader Yasser Arafat to denounce terrorism and Arab leaders to press Arafat.

“The president has called on all parties to step up” and do their part, Fleischer said. “All parties have an obligation to act. All parties, not just one.”

In turn, Bush stepped up his diplomacy with Arab leaders. He spoke by phone Thursday with the king of Bahrain about the continuing tension in the region, Fleischer said, and scheduled an April 17 meeting in Washington with the prime minister of Lebanon.

Bush has given Powell maximum flexibility to try to get the parties talking again, Fleischer said. “There is no guarantee of success. … Give the secretary time, and we’ll see how events unfold,” he said.

In Madrid, Powell met with Russian Foreign Minister Igor Ivanov. According to a senior U.S. official speaking on condition of anonymity, the Russian leader told Powell that Moscow would use its weight with Syria, Iran and the Lebanese to ask them to curb violence along the Lebanese border with Israel. Another battle front is in danger of opening in that area.

Powell and Ivanov also discussed a developing U.S.-Russian accord to reduce both nations’ long-range nuclear weapons.

But Ivanov made clear there was no agreement yet on the format for each country to cut warhead stockpiles to a range of 1,750 to 2,250 over 10 years each  or on the disposition of the warheads.

He reaffirmed Russia’s interest in a “legally binding” document and said, “The Russian side stands for making the reductions real, not virtual.”

Ivanov pledged Moscow’s support for Powell’s peace mission and said he will be in Washington in early May to continue arms talks with Powell.

U.S. and Russian arms experts, meanwhile, will meet in Moscow next week to continue working on details of an agreement, Powell said.

The looming arms control accord is the projected centerpiece of President Bush’s visit to Russia for a late-May summit with Russian President Vladimir Putin.

The agreement will be legally binding, as urged by Moscow, will require congressional approval and will have provisions of earlier treaties with the Soviet Union that provide for monitoring to ensure that the deal is being kept.

“It will be short, to the point,” Powell said.

Brushing aside Sharon’s assertion that seeing Palestinian leader Arafat would be a “tragic mistake,” Powell had said Wednesday that his mission was “not in the least in jeopardy” and that he hoped Sharon would facilitate the meeting.

He also said he hoped Sharon would ease restrictions on Arafat’s confinement in Ramallah, on the West Bank, to allow him to communicate more readily with other Palestinian leaders.

Before Wednesday, Bush had demanded several times that Sharon withdraw his troops from recently occupied Palestinian-controlled towns. They remained in the West Bank’s four major population centers Wednesday, although the defense ministry announced they were leaving several areas.

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

As he trekked through the Middle East and North Africa this week and then detoured to Spain, Powell made plain that objectives of his tour include renewing security cooperation between Israel and the Palestinians, tapping Saudi Arabia for help in rebuilding Palestinian facilities and organizing a worldwide relief effort for Palestinians.

He also is offering a small group of U.S. monitors, possibly drawn from the State Department, to keep tabs on a cease-fire. But Powell said they would not be drawn into clashes between Israel and the Palestinians.