AMMAN,JORDAN — AMMAN, Jordan -- Secretary of State James A. Baker III increased pressure on Palestinians yesterday to join in a regional peace conference, saying they had the "most to lose" if the process falters and avoiding any demand that Israel compromise further.
A delegation of three prominent Palestinians withheld a decision in a four-hour meeting with Mr. Baker in Jerusalem but said later that they could have a response "in days."
At a joint news conference here with King Hussein, who is willing to ease Palestinian participation with a joint Jordanian-Palestinian delegation, Mr. Baker said, "In our view, Palestinians have more to gain from a viable and active peace process than do almost anyone else."
He added, "Palestinians have the most to lose if there is no process."
A stronger message has been delivered privately, a senior administration official told reporters, noting: "History is replete with Palestinian rejections of prior opportunities. . . . Their position has not improved as a result; it has deteriorated."
King Hussein joined in applying pressure to the increasingly isolated Palestinians, saying: "The time has come for Palestinians to decide on their participation."
The king himself stated his willingness, previously understood but never expressed directly, to negotiate face-to-face with Israel as part of the peace process sponsored by the United States and the Soviet Union.
The increased pressure is aimed less at Palestinians in the Israeli-occupied territories, whose desperate condition makes them want direct talks with Israel, than at the Tunis-based leadership of the Palestine Liberation Organization.
The key issue blocking a peace conference is the question of who would speak for the Palestinians.
Israel refuses to participate if the Palestinians are represented by someone linked with the PLO, a resident of occupied East Jerusalem or a Palestinian from outside the territories.
Thursday, Israeli Prime Minister Yitzhak Shamir gave a conditional "yes" to the U.S. plan and is to seek formal Cabinet approval tomorrow.
Hints of compromise were made on both sides yesterday.
Defense Minister Moshe Arens, interviewed on Israel radio, suggested that a Jerusalem-born Palestinian would be acceptable as a representative of Jordan.
The Palestinians also hinted at a compromise-in-the-making over who would represent Palestinians at the talks, a compromise that could resolve one of the major procedural issues threatening to prevent the peace conference from taking place.
"We have the feeling there is no problem reaching a conclusion," said Faisal Husseini, a Palestinian activist who was part of a three-member delegation that met with Mr. Baker for nearly four hours. Mr. Husseini predicted that an answer would be given "in days, not weeks, not months."
Mr. Baker outlined Israel's conditions in his meeting yesterday with Palestinians. As outlined by Mr.Husseini, Mr. Baker told the Palestinians that they could indeed decide who would represent them, but he also beseeched them to be aware of Israel's demands when drawing up the list of names.
If all worked according to Mr. Baker's plan, the Palestinians would present a list acceptable to themselves and also to Israel, without Israel's being able to claim that it exercised a formal veto over the names.
"The principal position is that no one has the right to veto, to vet, to impose people," said Hanan Ashrawi, a West Bank university professor who met with Mr. Baker. "I think he is expecting us to put together a delegation that would be acceptable to everybody."
Mr. Baker's meeting with the three Palestinians got into an un-precedented level of detail, a senior administration official said.
Gratified by Israel's conditional acceptance of U.S. terms for a peace conference, Mr. Baker seemed unwilling to put further heat on Israel to compromise on the makeup of the Palestinian delegation.
While not publicly agreeing with Israel's position, he noted that Israel, Syria, Jordan and Lebanon all had agreed to join in the peace conference, which would be followed by direct bilateral and multilateral talks involving Arabs and Israel.
Like Mr. Shamir, the Palestinians asked Mr. Baker to put certain assurances for the conference in writing. The Palestinians want a written guarantee that the peace talks will implement United Nations resolutions calling for Israel to exchange captured territory for a formal peace.
Israel has agreed to using the U.N. resolutions as a framework but maintains that they do not require it to give up territory.