U.S. Secretary of State John Kerry ended his latest intensive peace-making mission to the Middle East Sunday without an agreement between Israel and Palestinians on the resumption of their long-stalled peace talks. At a press conference prior to leaving Israel, Kerry said there has been \"some progress\" during his three-day shuttle diplomacy aimed at restarting the peace process. \"With some extra work, the beginning of the negotiations is within reach,\" Kerry said at a press conference held at the Ben Gurion Airport near Tel Aviv before departing to his next destination. \"We have started out with major gaps and have narrowed them down. There are some more details to figure out but I\'m certain we \'re on the right track,\" he added. The top U.S. diplomat also acknowledged that during his back and forth travels between Jerusalem and Amman, Jordan, meeting with Israeli and Palestinian leaders, he \"was impressed by their genuine commitment.\" Kerry added that it\'s not possible to keep the status quo intact. \"We don\'t have time, time is threatening the situation on the ground. This leads to lack of trust and allows hostile factors to make an impact and close the window of opportunity.\" A diplomatic source in Jerusalem said that Kerry\'s visit ended up in \"disappointment\" despite the statement about slight progress in talks. \"Kerry wanted to announce a four-way summit, something that would mark the beginning of a new chapter. But there are still significant differences on several aspects so his grand announcement shrunk to an insignificant statement,\" the source told Xinhua. During this visit, Kerry held separate talks three times with both Israeli Prime Minister Benjamin Netanyahu and Palestinian President Mahmoud Abbas. He met with Netanyahu for six hours on Saturday evening and met with Abbas in Ramallah on Sunday noon. Palestinian sources said at the end of the meeting that no breakthrough was achieved. This has been Kerry\'s fifth visit to the region in the past three months. Earlier on Sunday, Netanyahu said during the beginning of the cabinet meeting that any future peace agreement would be brought to a national referendum. \"Israel is not the one blocking the peace talks,\" he said, adding that he is ready \"to start negotiations immediately without preconditions.\" The Palestinians have demanded the release of Palestinian prisoners, a freeze of the construction in the settlements and a statement that the talks will be based on a future Palestinian state established on lands occupied by Israel amid the 1967 Mideast War. The Israel-Palestinian peace talks collapsed in late 2010 after the Israeli government refused to extend a freeze on settlement building in the West Bank and East Jerusalem. It seemed on Saturday that there might be a breakthrough in the talks, and both Israeli and Jordanian media reported about a possible quadruple peace summit taking place in Jordan next week, but the sides appear to be too far apart. Israel\'s Walla! news website reported on Sunday that Netanyahu doesn\'t agree to the release of some Palestinian prisoners who have carried out terrorist attacks with many casualties, whereas the country\'s Ynet news website claimed the problem is mainly to do with the demand for Israel to announce a freeze of its construction in the settlements.