US Secretary of State John Kerry is due to meet with officials from Arab nations that he regards as essential to his push to get Israelis and Palestinians to resume peace talks.
His sixth visit to the region since taking office will continue on Wednesday, but US officials declined to confirm which countries would be represented at the meeting but said they were likely to include Bahrain, Egypt, Jordan, Lebanon, Qatar and Saudi Arabia.
A day earlier, Kerry and Palestinian President Mahmoud Abbas spoke for five hours in Amman over an Iftar dinner, the evening meal with which Muslims break their daily fast during Ramadan.
When Kerry met the group last on April 29, they made a concession to Israel by saying Israel and the Palestinians could swap land rather than conform exactly to their 1967 borders.
Previously, the group had insisted on a return to the 1967 lines and had not endorsed land swaps, although it has long been assumed that these would be part of any peace agreement.
Kerry and Abbas on Tuesday discussed Israeli-Palestinian peace, bolstering the Palestinian economy and the recent upheaval in the Middle East, a senior State Department official said without giving details, in keeping with Kerry's desire to keep his consultations secret.
Israeli-Palestinian negotiations broke down in 2010 in a dispute over Israeli settlement building in the occupied West Bank and East Jerusalem, which the Palestinians want for an independent state.
After a round of shuttle diplomacy between Abbas and Israeli Prime Minister Benjamin Netanyahu at the end of June, Kerry has said that "with a little more work, the start of final status negotiations could be within reach".
However, Israeli officials said they were unaware of any plans by Kerry to visit Israel on his latest trip.
The group he will meet on Wednesday had supported a 2002 Arab League proposal that offered full Arab recognition of Israel if it gave up land seized in a 1967 war and accepted a "just solution" for Palestinian refugees.
That plan, rejected by Israel when it was proposed at a Beirut summit in 2002, has major obstacles to overcome.
Abbas has said that for new talks to be held, Netanyahu must freeze the settlements and recognise the West Bank's boundary before its capture by Israel in the 1967 Middle East war as the basis for the future Palestine's border.
Israel, seeking to keep major settlement blocs under any peace accord and citing security concerns, balks at those terms.
Kerry has sought to ensure that any new peace process would have the backing of the Arab League states, which, if they were to offer Israel a comprehensive peace, could provide a strong incentive for Israeli compromises.
Israel objects not only to a return to 1967 borders but also to the inclusion of Arab East Jerusalem in a Palestinian state and the right of return of Palestinian refugees to what is now Israel.