US Secretary of State John Kerry held a final meeting with Palestinian leader Mahmud Abbas on Sunday as he wrapped up four-days of exhaustive shuttle diplomacy aimed at reviving direct peace talks.
But despite hours of talks with both Abbas and Israeli Prime Minister Benjamin Netanyahu, there was little sign of progress, with the Israeli press suggesting that Kerry's intensive engagement had failed to break the deadlock.
Over the last four days, Kerry has spent 13 hours in talks with Netanyahu, with the latest session between the two men and their aides lasting until nearly 4 am (0100 GMT) in a hotel suite overlooking Jerusalem's Old City.
A sleep-deprived Kerry then headed to the West Bank city of Ramallah to consult for the third day in a row with Abbas, a US official said. His previous two meetings with Abbas took place in Amman.
Talks began shortly after 0700 GMT, with Kerry and Abbas chatting briefly about a young Gaza singer who recently won the prestigious Arab Idol talent contest, bringing tens of thousands onto the streets. But neither man made any comment on the diplomatic issue, a correspondent at the scene reported.
Kerry was then expected to head straight to Ben Gurion airport near Tel Aviv where he was to hold a brief press conference before leaving for Brunei, US officials said.
Israel's army radio said Kerry's marathon efforts had so far failed to coax the sides back into direct negotiations after a gap of nearly three years.
The Palestinian leader is pushing Israel to free the longest-serving Palestinian prisoners, to remove roadblocks in the West Bank and to publicly agree to make the lines that existed before the 1967 Middle East war the baseline for negotiations.
Army radio said that Netanyahu was willing to consider just the first two conditions -- but only after talks were under way.
So far, Israel has flatly refused to countenance any return to the 1967 lines.
Army radio also said that despite Kerry's efforts, an Israeli committee was likely to push through a big discount for buyers of nearly 1,000 new homes which are due to be built in annexed east Jerusalem.
Last week, on the eve of Kerry's arrival, another local committee gave final approval to build some 70 homes in the same area.
As news of the plans reached Ramallah, Palestinian chief negotiator Saeb Erakat said they showed which side was blocking a return to the negotiating table.
"This is Netanyahu's response to everything Kerry said, to his ideas and to all his efforts," Erakat told AFP.
"We on the Palestinian side tried every possible effort to help Kerry succeed but it is obvious today ... that Netanyahu is putting an obstacle in front of Secretary Kerry's efforts."
Kerry, who is wrapping up his fifth visit to the region since taking over the State Department in February, has made the elusive goal of Middle East peace a top priority.
He had been due to fly to Abu Dhabi on Saturday for a meeting on the Syria crisis, but cancelled his plans to spend more time shuttling between Netanyahu and Abbas.
"Kerry is willing to put in the legwork necessary to move this process forward in a meaningful way," a US official said on condition of anonymity.
US officials have been tight-lipped about the substance of Kerry's meetings, fearing that any public statements could put at risk his efforts.
On Kerry's all-night meeting with Netanyahu, a US official said only that the two discussed a "wide range of issues related to the peace process" over a dinner of hummus, pita and sea bream.
Kerry's immediate aim is to find a way to draw the two sides back into direct negotiations which collapsed several weeks after they were launched in September 2010 in a dispute over Israel's settlement building.
Although several ministers have suggested that Netanyahu increasingly saw a strategic interest in resuming peace talks, he is currently at the helm of a both a party and a coalition of hardliners, many of whom oppose a Palestinian state.
Economy Minister Naftali Bennett, who heads the far-right Jewish Home party, recently described the Palestinian demands for a state as "shrapnel in the buttocks" -- a problem Israel simply had to keep suffering through.
Abbas too faces internal dissent, with the Islamist Hamas movement, which controls the impoverished Gaza Strip, strongly criticising him for pursuing talks.