After three days of lengthy meetings with Palestinian Authority President Mahmoud Abbas and Israeli Prime Minister Benjamin Netanyahu in Jerusalem and Ramallah, US Secretary of State John Kerry will travel to Jordan and Saudi Arabia on Sunday to discuss his efforts to reach Israeli-Palestinian peace, as well as other regional issues.

Kerry said he would return to Jerusalem Sunday evening, and may stay for several days before flying back to Washington later in the week, he told reporters in Jerusalem on Sunday morning.

“This has been a productive couple of days with very, very intensive talks,” he said.

Addressing skepticism on both sides about the probability for reaching a final agreement, he added, “These issues are not easy. If it was easy it would have been resolved a long time ago. These are complicated issues that involve…the survival of peoples. This conflict has gone on too long, so positions have hardened. Mistrust obviously exists at a very high level. So we have to work through that and around that and over that.”

He urged leaders to avoid the spate of criticism each side has leveled at the other in recent weeks, with Netanyahu accusing the Palestinian leadership of anti-Jewish incitement, and Palestinians threatening repeatedly to walk away from the talks over settlement construction.

“Now is not the time to get trapped in the sort of up-and-down of the day-to-day challenges,” Kerry said. “This does not lend itself to a daily tick-tock. We don’t have the luxury of dwelling on the obstacles that we all know could distract us from our goal. What we need to do is lift our sights and look ahead and keep in mind the vision of what can come and if we can move forward.

“I know there are those out there on both sides who question whether peace is possible. I know there is a high level of cynicism, reservations about the possibilities. But it is clear to me that we can work to bridge the remaining gaps that do exist,” he insisted.

Kerry said both Abbas and Netanyahu “have already made important… and courageous decisions, difficult decisions” in the negotiations.

“The path is becoming clearer,” he added, “the puzzle is becoming more defined, and it is becoming much more apparent to everybody what the remaining tough choices are, and what the options are with respect to those choices. But it takes time to work through these things.

A US official told Haaretz over the weekend that one of the main obstacles holding up the framework deal is each side’s demand that their reservations over the framework appear as a separate appendix in the final text, rather than as part of the main text which details the areas of common ground in the talks.

“It is essential that if there are reservations, they will be part of the framework, not a separate part. Otherwise, it would damage the agreement. For example, if the framework includes a clause stating that the negotiations will be based on the 1967 borders, we cannot agree to a reservation stating that one of the sides opposes this,” the official said.

Any agreed framework would not be a signed document, but would address all core issues, including the borders between Israel and a future Palestine, security, Palestinian refugees, and conflicting claims to Jerusalem, the official said. The official also said if the parties agreed on a framework for negotiating a final peace deal, it might not be made public to avoid exposing the leaders to political pressures at home.

But those pressures are already ramping up.

Jewish Home Knesset faction chair MK Ayelet Shaked said Sunday morning that her party would not remain in the coalition if the government adopts a framework agreement “based on the ’67 lines.”

“A government that accepts the ’67 lines is a government of national suicide,” she said.

Kerry reiterated long-standing Obama administration commitments to Israel’s security and Palestinian independence.

“The security of Israel is always paramount in my mind, in our mind. For 29 years, I had the privilege of serving in the United States Senate, and I’m proud to say I had a 100% voting record with respect to those issues concerning Israel. And I don’t intend to change that now. Israel’s security is critical and the United States’ relationship is ironclad.”

But, he added, “so is our concern for the people of Palestine, for the Palestinians and their future. And I can guarantee all parties that President [Barack] Obama and I are committed to putting forward ideas that are fair, that are balanced and that improve the security of all of the people of this region.”

He declined to give details about what difficult decisions the leaders had made, saying, “We are not going to negotiate this in public. But I can tell everybody all of the core issues are on the table.”

Kerry’s talks on Sunday with Jordan’s King Abdullah II and Saudi Arabia’s King Abdullah are likely to also touch on the civil war in Syria, rising violence in Iraq, and Iran’s nuclear program. Kerry is reportedly to meet next week with Arab League representatives and discuss the Israeli-Palestinian peace process and other regional issues.

Times of Israel staff and AP contributed to this report.