American efforts to broker a resumption of peace talks ended on Sunday without a breakthrough, a senior Palestinian official said, although US Secretary of State John Kerry hailed "real progress".

Kerry has spent the past four days locked in intensive shuttle diplomacy between the Israeli and Palestinian leadership in a bid to draw the two sides back into direct negotiations after a gap of nearly three years.

But after 13 hours of talks with Israeli Prime Minister Benjamin Netanyahu, and about six hours with Palestinian president Mahmud Abbas, Kerry's efforts ended on Sunday with no tangible signs of progress.

Speaking in Ramallah after Kerry's final meeting with Abbas, chief Palestinian negotiator Saeb Erakat said there had been "no breakthrough so far".

"There is still a gap between the Palestinian and Israeli positions," he told a news conference, adding Israel wants "to resume negotiations while settlements continue".

Kerry insisted, however, that his talks in Jerusalem, Amman and Ramallah, which began on Thursday evening, had been "very positive".

"I am pleased to tell you that we have made real progress on this trip and I believe that with a little more work, the start of final status negotiations could be within reach," he told reporters at Ben Gurion airport just before leaving for Asia.

"We started out with very wide gaps and we have narrowed those considerably.

"We have some specific details and work to pursue but I am absolutely confident that we are on the right track and that all the parties are working in very good faith in order to get to the right place," said Kerry.

"We have all agreed that the best way to serve this effort is not to be floating ideas or the possibilities out there for everybody to tear apart."

Asked if Israel's settlement building hampered efforts to achieve a breakthrough, he said. "The answer is no, there are any number of obstacles, but we are working through them."

Kerry also pledged to return at some point to the region "because both leaders have asked me to," and refused to set a time framework to his diplomatic efforts.

"We're not going to get stuck with artificial deadlines," he said. "That's a big mistake."

Israel's Channel 2 television and Palestinian sources said Kerry would be back in the region "in a few days".

The Palestinians described his final meeting with Abbas on Sunday as "positive and profound". Sanding next to Abbas, Kerry said: "We both feel good about the direction."

Kerry spent most of his final night in Jerusalem cooped up in a hotel room with Netanyahu for a seven-hour session which ended just before 4:00 am (0100 GMT).

A few hours later a sleep-deprived Kerry headed to Ramallah for a third and final meeting with Abbas. Their previous two meetings took place in Amman.

Netanyahu, meanwhile, insisted Israel was not blocking a return to negotiations.

"We are not putting up any impediments on the resumption of the permanent talks for a peace agreement between us and the Palestinians," he said in remarks released by his office.

"There are things that we will strongly insist on in the talks themselves, especially security," he said, stressing any agreement would be "submitted to the people for a decision".

Israel's army radio said Netanyahu had refused to give ground on several key issues for the Palestinians.

Abbas has been pushing for Israel to free the longest-serving Palestinian prisoners, remove roadblocks and publicly agree to make the lines that existed before the 1967 Six-Day War the basis for talks.

The radio said Netanyahu was willing to consider 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.

On the eve of Kerry's arrival, a local committee gave final approval to build some 70 homes in east Jerusalem.

Kerry toured the region five times since taking over the State Department in February and scrapped a planned trip Abu Dhabi on Saturday to devote more time to his shuttle diplomacy.

"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.