Ban said he would also go to Jordan which has been hosting informal talks between the rival sides in the Middle East conflict.

The UN secretary general did not give details of his tour, but he is expected to arrive in Amman on Monday after attending the African Union summit in Addis Ababa at the weekend.

"My visit comes at an important moment," Ban told a press conference. "I will be there to encourage both sides to engage in earnest and create a positive atmosphere for moving forward."

Israeli and Palestinian negotiators were to hold a final round of informal talks on Wednesday ahead of the expiration of a deadline set by the Middle East Quartet of diplomatic peacemakers -- the United States, United Nations, Russia, and European Union -- of a new initiative to relaunch talks.

Palestinian leader Mahmud Abbas said following talks with Jordan's King Abdullah II in Amman on Wednesday that Palestinians could return to formal negotiations if Israel would agree to set out borders.

The Palestinians halted formal talks in September 2010 when Israel ended a moratorium on settlement building in the Palestinian territories.

Abbas made the remarks after discussions with King Abdullah II, and ahead of a fifth round of exploratory talks between Israeli and Palestinian negotiators who are seeking ways to restart direct negotiations between the two sides.

"If we determine the borders it is possible to return to negotiations, but the Israelis don't want to determine the borders," Abbas said according to remarks carried by WAFA news agency.

The Palestinians have said it would be pointless to hold talks without a framework for discussions, and want Israel to agree to use the lines that existed before the 1967 Six-Day War as the basis for discussions on future borders.

They have also insisted in the past that they will not return to direct talks, which have been on hold since the end of September 2010, without an Israeli settlement freeze, though Abbas made no reference to that demand in his comments on Wednesday.

Abbas's talks with King Abdullah came shortly before Palestinian negotiators Saeb Erakat and Mohammed Shtayeh were to meet Israel's Yitzhak Molcho for a fifth round of "exploratory talks."

The discussions were intended to lead the parties back to talks under a timeline announced by the peacemaking Quartet on October 26, which gave both sides three months to submit proposals on territory and security.

The Palestinians say they have submitted their documents, and accuse Israel of failing to reciprocate.

But Israel says it considers the three-month period to have begun from the first round of exploratory talks on January 3, with officials reportedly saying they would present their outlines on borders and security at some point in March.

Abbas said the Palestinians had been clear about their demands on security, and that a period of evaluation would follow what he and his officials have insisted will be the final round of exploratory talks today.

"On security, we are ready for any Israeli requests on the issue of security, on the condition that not a single Israeli will be on Palestinian land," he said.

"After the end of the exploratory meetings there will be a phase of evaluations and consultations with His Majesty King Abdullah II, and we will have a meeting of the Arab League Follow-up Committee on February 4," he said.

"There we will take the decision."

In recent weeks, there have been reports suggesting high-level diplomatic discussions were under way about a broad deal intended to keep the Palestinians talking.

The reported deal could see Israel release up to 150 Palestinian prisoners, including senior political officials, in exchange for the Palestinians agreeing to waive their demand for a settlement freeze and dropping their bid for full UN state membership.