US Secretary of State John Kerry has rushed to the Middle East for a surprise visit aimed at rescuing his diplomatic efforts, as peace talks approached a critical point.
The State Department said Kerry was flying from Paris to Tel Aviv on Monday for meetings with Israeli and Palestinian leaders that may be held in Jerusalem and Ramallah.
Kerry has been working frantically in recent days trying to salvage the embattled peace process.
A senior US official said Kerry spent the morning in Paris speaking with Israeli and Palestinian leaders, as well as with the White House, before deciding to return to the region.
The official spoke on condition of anonymity because he was not authorised to discuss the matter with the media.
US mediators have been holding urgent talks to resolve a standoff over a promised Israeli prisoner release and to find a formula to extend the talks beyond a current late-April deadline.
Risk of collapse
If the prisoner release, which was scheduled to happen by the end of March, does not take place then the negotiations risk collapsing in the coming weeks.
The Palestinian leadership set up a meeting to discuss developments on Monday evening in Ramallah in the occupied West Bank. There was no immediate comment from the office of Israel's prime minister.
Under heavy pressure from Kerry, Israel and the Palestinians agreed last July to hold nine months of peace talks, setting a late-April deadline for a final agreement.
When that became unrealistic, Kerry scaled back his goals and said he would aim for a preliminary "framework" agreement by April, with the goal of continuing negotiations through the end of the year to iron out the final details of a deal.
But even that more modest goal has run into trouble due to a snag over the prisoner release.
When the talks began last summer, Israel promised to free 104 long-serving Palestinian prisoners in four stages.
After carrying out the first three releases, Israel has baulked at releasing the final group without a Palestinian commitment to extend talks.
'Not in good fatih'
The prisoner issue is deeply emotional for both sides.
Israeli officials say they are under no obligation to carry out the final release because of what they say is a Palestinian failure to negotiate in good faith.
The Palestinians consider the roughly 5,000 Palestinians held by Israel to be heroes and freedom fighters.
Israel considers them terrorists. The prisoners have all served lengthy terms after being convicted of bloody attacks on Israelis and the scenes of freed prisoners returning to jubilant celebrations have angered the Israeli public.
The Palestinians say Israel is obligated to carry out the release. They are demanding additional gestures, including the release of another 1,000 prisoners and a halt to illegal settlement construction on occupied lands, in return for extending peace talks.