THE United States wants Palestinians to participate in the planned Middle East peace conference as part of joint delegation with Jordan, but this proposal cannot be worked out until the US refines its positions on which Palestinians can attend and whether East Jerusalem will be under discussion, according to Jordanian and Palestinian officials.At a meeting in Algiers two weeks ago, the Palestinian "parliament in exile" agreed in principle to have Palestinians attend the conference, which was seen as a breakthrough. But current difficulties in working out how they will attend suggest that major issues still have not been resolved. Over the weekend Jordan and the Palestine Liberation Organization (PLO) concluded three days of talks without reaching an agreement on formation of a joint Jordanian-Palestinian delegation. Jordan's King Hussein and PLO chairman Yasser Arafat are scheduled to meet this week to discuss the delegation. There seems to be some disagreement between the two sides, since the Palestinians are trying to get Jordan's help in gaining assurances from the US, but the Jordanians feel they are unable to do much. Jordan is hinting that it may attend the conference even if the Palestinians do not. PLO officials also say the US must assure them that Palestinian delegates will be seen as representatives of their people, and not as Palestinian individuals on a Jordanian team. The PLO says it wants to make sure that Palestinian national rights are addressed. "We are still waiting for the American answers for these sensitive questions prior to a final decision by the PLO Central Council," says PLO executive committee member Yasser Abed Rabbo. The PLO expects US Secretary of State James Baker III to address the PLO's questions when he meets with Palestinian leaders Faisal Husseini and Hanan Ashrawi - who live in the occupied territories - in Washington later this week. Meeting in Algiers two weeks ago, the Palestine National Council (PNC) gave the green light for Palestinian participation at the US-sponsored peace conference, but the final declaration fell short of a fullfledged commitment. Even though the PLO has agreed in principle to play an indirect - and most probably invisible - role at the talks, it has demanded that it appoint the Palestinian side, which it insists should be treated on a footing equal to the other delegations. The PLO also insists that Palestinian delegates represent Palestinians inside and outside Israeli-occupied territories, including East Jerusalem. But the Israelis have said they will not attend if the PLO is there, and that any Palestinian must be from the occupied lands - but not East Jerusalem. In addition to the PLO's terms for "adequate" Palestinian representation, the organization is demanding that the status of Israeli-annexed East Jerusalem be up for discussion, and that the Israelis freeze Jewish settlements in the territories. But "this is an area where Jordan is unable to do anything" prior to the conference, says a senior Jordanian official. According to Palestinian and Jordanian officials King Hussein has promised that Jordan will support the PLO's demands both before and after the conference starts. But while the PLO may block Palestinian participation if its demands are not met, the Jordanians say they may still take part in the peace parley and raise the issues there. Jordanian Prime Minister Taher al-Masri said in a television interview this week that Jordan understood why the PLO was more hesitant in allowing Palestinian participation at the conference. "The Palestinian situation is more complex than the Jordanian position ... after all, the Palestinian cause is very complex and hence the Palestinian emphasis on American assurances," he told Algerian television. In an attempt to justify his reservations, Mr. Arafat said in the same interview that the Palestinians were not putting forward preconditions, but would not accept a peace conference according to Israeli terms. Arafat was apparently trying to win Arab, or at least Jordanian support for his position, lest the PLO be accused of undermining the process. But while constraints on Palestinian role and the continuing Israeli settlements are viewed by the PLO as unacceptable "Israeli terms," it is unclear what would stop Jordan from going. Jordanian officials have said that they will insist that settlement will top the agenda at the negotiating table, but have never stipulated that a freeze on settlements is a prerequisite for Jordanian participation. Both Jordan and the PLO, so far, seem keen on preventing a bitter falling out. "There are no differences between us and Jordan.... Our differences are with the US," says PLO official Abdullah Hourani.