WASHINGTON (AP)—Yasser Arafat and Yitzhak Rabin, wary partners in peace after decades of enmity, stood ready to reshape the Middle East with the ceremonial signing of an agreement that will set the stateless Palestinian people on the road to independence.

‘‘I … am hopeful that this will lead to peace,’‘ a beaming Arafat declared Sunday after stepping off a plane at Andrews Air Force Base outside Washington. It marked the PLO leader’s first trip to the United States in 19 years.

And Rabin, as he left Israel for Washington, said of the accord, ‘‘I am behind it full-heartedly, knowing the chances, the prospects, at the same time the difficulties and the dangers in which we embark.’‘

For Rabin—the general who 26 years ago captured the West Bank and Gaza Strip, and Arafat—the guerrilla leader who now hopes to free them from Israeli rule, Monday’s signing of an Israel-PLO accord on self-rule for Palestinians marks a moment of hope and trepidation.

Along with President Clinton, Arafat and Rabin will share a stage on the South Lawn of the White House before 3,000 guests—former Presidents Carter and Bush, dozens of foreign ministers, and legions of Americans, Arabs and Jews who have tried to make peace in the Middle East—and millions of TV viewers around the world who will watch the ceremony live.

The prospect of the encounter between Rabin and Arafat, sworn enemies until three days ago when they signed a mutual recognition pact between Israel and the PLO, generated intense speculation and disbelief Sunday amid the frenzied preparations for the signing.

‘‘An awful lot of taboos are being broken in the last few days,’‘ said Secretary of State Warren Christopher. ‘‘We’re all blinking our eyes at how much is new,’‘ said Christopher, who along with Russian Foreign Minister Andrei Kozyrev will witness the signing.

The document will likely be signed by Israeli Foreign Minister Shimon Peres and Arafat’s top aide, Mahmoud Abbas. White House workers were dusting off the desk used to ink the 1979 peace agreement between Israel and Egypt—the only Arab-Israeli peace ever signed.

On everyone’s minds was whether Rabin and Arafat would shake hands.

Rabin’s response, when asked in a CNN interview, was a grudging ‘‘if it will be needed.’‘ And Arafat? ‘‘Why not,’‘ he told The Associated Press in an interview aboard the plane taking him to Washington. ‘‘With who are we going to make peace? With our enemies.’‘

One thing was made clear Sunday: Arafat might well wear his trademark black-and-white headdress (called a kaffiyeh), but could not carry his pistol. The White House policy against handguns would apply, warned a presidential aide.

‘‘I think it was much more difficult for him to change his garb than to change the real politics behind it, but symbols sometimes are very difficult to fade out,’‘ said Arafat’s aide, Nabil Shaath.

For Rabin, too, it’s a fundamental adjustment. ‘‘I wouldn’t say that it will be easy to me. I don’t pretend that I can change in few days,’‘ he told CNN. But, he added, ‘‘I would like to give it a chance.’‘

The White House was careful to protect its long relationship with Israel. After the ceremony, Clinton was meeting privately with Rabin. No consideration was given to a similar meeting with Arafat; the ceremony alone is ‘‘a revolution in terms of our relationship with the PLO,’‘ a senior administration official said.

Even before Rabin and Arafat set foot here, there was trouble. Three Israeli soldiers were killed by Muslim militants opposed to the accord, and the thorny dispute over the future of Jerusalem surfaced.

While praising the self-government agreement as ‘‘an important, positive and correct step,’‘ Arafat also told reporters before leaving Tunis for Washington that the agreement would lead to ‘‘an independent Palestinian state, with Jerusalem as its capital.’‘

‘‘He can forget about it,’‘ was Rabin’s retort when told of Arafat’s prediction. ‘‘I assure Chairman Arafat that … Jerusalem will remain always united under Israel’s sovereignty and our capital forever.’‘

The future of the holy city is one of the issues which Israeli and PLO negotiators left to be decided at a later date.

On another track, Jordanian and Israelis officials met at the State Department Sunday on the final details of a document that ould serve as a framework for a peace treaty between them. Rabin predicted a probable announcement of that agreement on Tuesday.

The Israeli-Palestinian agreement foresees the election of a Palestinian council within nine months to run every day life for the 1.8 million Palestinians in the West Bank and Gaza Strip—which Israel captured from Jordan and Egypt in the 1967 Mideast war.

Within four months of the agreement taking hold, Israel will have withdrawn all its troops from Gaza and the biblical West Bank town of Jericho—where self-government will go into effect first.

Israel will also start pulling back its troops gradually from other Palestinian centers, handing control to a police force composed partly of former PLO fighters.

Not later than the start of the third year of self-government, Israel and the Palestinians will start negotiating the future sovereignty over the West Bank and Gaza.

But the accord is intentionally vague about many of the details still to be worked out, and Christopher said he would meet Monday with Arafat to start discussing the nitty gritty of the accord.

All sides made clear that the agreement’s success rests in no small measure on financial aid.

The World Bank estimates that development projects for the West Bank and Gaza will require up to $3 billion in the next few years. And Rabin said Israel would need several hundred million dollars to redeploy troops and build new roads—in addition to the $3 billion his government already gets in annual U.S. aid.

But congressional leaders made clear Sunday they would not come up with much, if any, of the money and that other countries would have to chip in.