American, Israeli and Palestinian leaders, locked for seven days in negotiations over a West Bank withdrawal, are aware that it would be difficult to end their summit talks at the Wye Plantation near Washington without clinching an agreement. US officials said some progress was made on Tuesday when President Bill Clinton and Jordan's King Hussein joined the marathon efforts to break 19 months of stalemate in the Middle East peace talks. However, officials were cautious about the final outcome of the summit. "We wouldn't still be at this if we didn't believe that both sides were serious about reaching an agreement," said White House spokesman Joe Lockhart. "That said, I'm not in a position to predict that the two sides will reach an agreement." Lockhart spoke shortly after Clinton returned at dawn yesterday to the White House from the Wye River conference centre on Maryland's eastern shore where he tried for 12 hours to push an accord between Israeli Prime Minister Binyamin Netanhayu and Palestinian leader Yasser Arafat. State Department spokesman James Rubin also cautioned reporters that while some obstacles had been overcome, Israeli and Palestinian leaders still had not made the hard decisions needed to clinch a deal. "It's certainly the most intensive phase yet but some significant gaps remain. We have overcome some obstacles, but an inch is as good as a mile in terms of not closing," Rubin said. The tug-of-war over the agreement that is taking shape centres on whether it should focus on Israel's security concerns or take a more comprehensive form, meeting Palestinian demands for certain Israeli commitments. "Either we reach a comprehensive agreement or else we are not going to sign," said Arafat's adviser, Nabil Abu Rudeina. He said that differences remained on several outstanding issues. US and Israeli officials said that while some secondary matters have been resolved, a gap still existed between the two sides on certain central issues, such as the scope of a third withdrawal from the West Bank and the so-called unilateral measures -- an allusion to the establishment of Israeli settlements in occupied territories. Palestinian officials, speaking to Al-Ahram Weekly, said their position was to insist on halting all construction and expansion of Jewish settlements, and to demand the establishment of a joint Palestinian-Israeli committee to determine the scope of a third redeployment. The Israelis, on the other hand, are adamant that the third redeployment should not exceed one per cent of West Bank territory or should be postponed until the final status negotiations. They are also calling for the Palestinian National Council to convene and cancel all anti-Israel provisions contained in the Palestinian National Charter. "We insist on clear commitments on a third withdrawal; we insist on clear commitments on all the interim questions -- Gaza airport, harbour and industrial zone, safe passage, release of prisoners and time-out on settlements," a Palestinian involved in the negotiations told the Weekly. "We are not here for a partial agreement and Arafat will not sign a partial deal." A State Department official explained that "there are a lot of linkages that get involved. Whether we can get some of them delinked is certainly an open question." However, Cable News Network [CNN] quoted Israeli and Palestinian officials as saying that a comprehensive agreement was being finalised. If secured, Israeli sources told CNN, the agreement could possibly be signed at the White House today. The view from Cairo is that no progress "in the real sense of the word" has been achieved yet. Egyptian officials believe that while Arafat has the right to make gestures to the US, he should make sure that the negotiations do not involve drastic and "unaffordable" concessions by the Palestinians. Egyptian diplomats concede that Cairo, out of concern at the prospect of the Palestinians making too many compromises, has chosen to keep a low-profile in this phase of regional peace-making. Indeed, analysts noted that Arafat, on the eve of the summit, did not make the usual trip to Cairo, which he traditionally visits before going into any major talks. Instead, he opted to visit Jordan for consultations with Crown Prince Hassan, who also received Netanyahu and his hawkish Foreign Minister Ariel Sharon. Foreign Minister Amr Moussa, answering reporters' questions in Cairo yesterday, said: "I trust that the Palestinian negotiating team, with Arafat at its head, is completely aware of the Palestinians' rights and will not decide to sign an agreement that contains serious concessions." Moussa stressed that any agreement reached at Wye Plantation should be one that meets with approval from public opinion in the region. "We hope that this [anticipated] agreement will be received here, by public opinion in the Middle East, with enthusiasm, or at least with satisfaction," the foreign minister said. Asked whether Egypt was keeping a low-profile compared to Jordan, Moussa responded: "I cannot say that Jordan is very much involved.". Mousa added that the US and Palestinian delegations were briefing Egypt on a daily basis. Hoda Tewfik in Washington, Tarek Hassan in Gaza, Dina Ezzat in Cairo