Chief Palestinian negotiator Saeb Erekat will head to the United States on Thursday to hold talks with top US officials over the crisis in peace talks.

Separately, Palestinian Premier Salam Fayyad is also heading to Washington where he is expected to meet Hillary Clinton ahead of a forum at the Saban Centre for Middle East Policy at which the secretary of state will speak about a new strategy for advancing the peace process.

Fayyad, who is to arrive sometime early on Friday, will also address delegates at the forum, alongside Israeli Defence Minister Ehud Barak, who left for Washington overnight.

The forum is set to take place just days after Washington admitted defeat in its efforts to secure an Israeli freeze on settlement building -- the Palestinians' condition for resuming direct peace talks.

Erekat is to arrive at around 1900 GMT on Thursday and will hold talks with Clinton as well as with other top officials at the State Department, Palestinian officials said. His Israeli counterpart, Isaac Molho, is already in Washington, Israeli media reports said, with both men expected to meet with US administration officials to discuss the crisis.

During his talks on Thursday with Egyptian President Hosni Mubarak, Palestinian president Mahmoud Abbas ruled out the possibility of a direct meeting between Palestinian and Israeli officials.  Abbas held his ground and insisted he would not talk with Israel unless there was a halt to settlement building during talks.

"We will not accept negotiations as long as settlements continue," Abbas told reporters in Cairo."We have made this clear to the Americans: without a halt to settlements, no negotiations."

With no chance of a new ban on Israeli settlement building, the direct peace talks have effectively collapsed, with US officials admitting the negotiations are likely to return to the indirect format they took earlier this year.

Direct talks had begun on 2 September after a 20-month hiatus, but lasted for just over three weeks before running into difficulties.