US President Bill Clinton has appealed for compromise in negotiations between Israel and the Palestinians as he met a frustrated President Yasser Arafat in Washington.

Mr Clinton said he would do whatever he could to achieve a comprehensive peace deal but added that "no one can get everything" if the peace process is to move forward.

Israeli withdrawals from occupied territory in the West Bank have again fallen behind schedule and there is pessimism about the possibility of meeting deadlines for progress towards a final status agreement.

Palestinian politicians have complained about what they see as Israeli prevarication and broken promises in implementation of agreements signed in Egypt last year.

The US president also sought to reassure Palestinians that their peace process would not be left in the wilderness while Syria and Israel were at the negotiating table.

"The issue between Israel and the Palestinians is at the core of the efforts to achieve peace in the Middle East," Mr Clinton told reporters at the start of his meeting with Mr Arafat at the Oval Office.

Mr Arafat, speaking through an interpreter, acknowledged there would be difficulties along the way, but said "there is also determination to reach a comprehensive, just and lasting peace".

The Palestinians are waiting for the interim hand-over of another 6.1% of West Bank land, but it is the future of the 60% still occupied by Israel and the sovereignty of Jerusalem which provide the real obstacles to progress towards peace.

'A formidable challenge'

Earlier, Mr Arafat held a "warm, positive and beautiful" lunchtime meeting at the home of Secretary of State Madeleine Albright.

The State Department's spokesman, James Rubin, described the prospects of a final Israeli-Palestinian peace agreement by September "a formidable challenge".

"But we have not given up hope. The people who do the work in this business have seen a lot of problems resolved in the final days of negotiation," Mr Rubin said.

Final status talks have made little progress in resolving four complex issues - demarcation of final borders, the status of Jerusalem, the fate of Palestinian refugees and the future of Jewish settlements on occupied land.

In parallel with Mr Arafat's meetings, his ministers are discussing bilateral economic matters with the Americans.

Joint committees will meet on Friday, chaired by Palestinian Planning Minister Nabil Shaath and US deputy assistant secretary of state Toni Verstandig.

The US president had planned to meet Israeli Prime Minister Ehud Barak himself later this week, along with Syrian Foreign Minister Farouk al-Shara.

But the third round of Israeli-Syrian peace talks was postponed indefinitely after the two sides failed to reach an agreement on a framework for Israeli withdrawal from the occupied Golan Heights