Israel and the Palestinians have no choice but to reach a full peace agreement and will put every issue on the table in order to do so, US Secretary of State John Kerry said Tuesday morning, as Israeli-Palestinian talks began in Washington.

“I’m convinced we can get there,” an upbeat Kerry said.

Calling the initial engagement positive and constructive, Kerry said the upcoming nine months of talks would seek to resolve all issues between the parties, seemingly shelving any notion of an interim agreement.

“The parties have agreed to remain engaged in sustained, continuous and substantive negotiations on the core issues,” Kerry told reporters at a press conference. “The parties have agreed that all the final status issues, all the core issues and all other issues are all on the table for negotiations.”

Kerry’s statement, made an hour later than planned, came after over three hours of meetings between the sides, including a joint session with US President Barack Obama at the White House.

Kerry said the sides would meet again in two weeks in Israel or the Palestinian Authority to begin the process of “formal negotiations.”

“A viable two-state solution is the only way this conflict can end and there is not much time to achieve it,” he said.

Justice Minister Tzipi Livni, representing the Israeli side along with Yitzhak Molcho, Prime Minister Benjamin Netanyahu’s personal envoy to the talks, said she was “hopeful for talks but could not be naive, we cannot afford it in our region.”

“It’s not going to be easy. It’s going to be hard with ups and downs, but I can assure you that in these negotiations it is not our intention to argue about the past but to make decisions for the future,” she said.

Palestinian negotiator Saeb Erekat said the Palestinians were happy to see that all issues would be discussed in the talks, which are expected to last nine months.

“I am delighted that all final status issues will be resolved, without any exceptions,” he said. “It’s time for the Palestinians to live in peace, freedom and dignity within their own sovereign state.”

Both Livni and Kerry addressed the deep skepticism that has surrounded the talks, the first round in three years and the latest of a series of negotiations led by the US, but said overcoming the pessimism was paramount to success.

“While I understand the skepticism, I don’t share it and I don’t think we have time for it,” Kerry said.

All three diplomats spoke in broad terms, notably avoiding mention of the 1967 borders, Jerusalem, settlements or any other issues that will form the heart of the talks. Livni and Kerry both alluded to Israel’s decision on Sunday to release 104 Palestinian prisoners, many of them convicted on terror charges, to meet Ramallah’s precondition for talks.

“A courageous act of leadership by Prime Minister Netanyahu made the visit here and the beginning of negotiations possible,” Livni said at the press conference.

Tuesday’s talks lasted for approximately three hours, with the last 45 minutes devoted to trilateral negotiations between Kerry, Livni and Erekat.

The one-day summit was the first high-level engagement between the sides since 2010. Livni told Israeli news site Ynet that the discussion was “held under eight eyes without a mediator. It was good.”

The White House meeting lasted a bit less than half an hour, with US Vice President Joseph Biden, Kerry, National Security Administration Chief and former UN envoy Susan Rice, NSC Coordinator Philip Gordon and the top American negotiator, Martin Indyk, present on the American side.

White House Spokesman Jay Carney said, “The president used this opportunity to convey his appreciation to both sides for the leadership and courage they have shown in coming to the table, and to directly express his personal support for final-status negotiations.”

Obama, Carney said, emphasized that there was “much to do in the days and months ahead.”

Obama’s meeting with the sides was a shift for the president, who has mostly stayed on the sidelines during the last several months while Kerry has shepherded the two sides to a resumption of talks.

The White House reiterated that Obama was “engaged” in the process, even if he had delegated the direct responsibility for overseeing negotiations to Kerry.

Before seeing Obama on Tuesday, the negotiators met together without American mediators. After leaving the White House they returned to the State Department for a three-way meeting with Kerry and top aides.

Officials from all parties expressed cautious optimism about the negotiations’ prospects for success as they began Tuesday morning.

Speaking from Latvia on a state visit Tuesday, President Shimon Peres said Israel was hoping for the best.

“In the 65 years of Israel’s existence, during which we were forced to fight seven wars, we have always aspired for peace and democracy –- the negotiations started yesterday and we hope for the best,” Peres said. “Israel’s desire, and the purpose of the talks, is the creation of two states for two peoples — living side by side with economic and scientific cooperation.”

Hours after the opening round of talks concluded Tuesday, Senator Dianne Feinstein (D-CA) pitched a resolution commending Kerry for jumpstarting the negotiations and called on both sides to push for a two-state solution to guarantee lasting peace.

The resolution was co-sponsored by Senators Tim Kaine (D-VA) and Martin Heinrich (D-NM). A day earlier, Kaine took the reins of the Senate Foreign Relations Committee’s Mideast Subcommittee.

“Resolving the longstanding conflict between the Palestinians and Israelis is in the fundamental interest of the United States,” Feinstein wrote in a statement Tuesday evening. “Secretary Kerry’s efforts to get both sides to the negotiating table have paid off, but negotiators will need to make very difficult decisions over the next nine months to reach a lasting two-state agreement.”

The senators declared that “a two-state solution is the only outcome to the Israeli-Palestinian conflict which can ensure the State of Israel’s survival as a secure, democratic homeland for the Jewish people, and fulfill the legitimate aspirations of the Palestinian people for a state of their own.”

The resolution, which must still be approved by the Senate, also stated that the “achievement of a two-state solution that would enhance stability and security in the Middle East is a fundamental United States security interest.”

On Monday, Peres called Indyk, the newly appointed US envoy to the negotiations, and wished him luck on his mission to help the sides reach an agreement. “You took upon yourself a mission important like no other and I thank you for it,” Peres told Indyk, a former ambassador to Israel. “I have my fingers crossed for your success and for the progress of the negotiations that will bring a peaceful solution to both sides.”

Peace talks kicked off informally in Washington Monday evening with an Iftar dinner, a traditional dinner marking the close of the daily fast during the month of Ramadan.

Livni described the mood at the dinner as “very good” and even friendly, emphasizing that both sides were “serious” and had learned from personal experience in earlier rounds of talks.

The Associated Press contributed to this report.