Kerry Says Goal Is Mideast Peace Deal Within 9 Months T.J. Kirkpatrick/Getty Images The Palestinian negotiator Saeb Erekat, right, and the Israeli justice minister Tzipi Livni left the White House with Secretary of State John Kerry, the Palestinian negotiator Mohammad Shtayyeh, the Israeli negotiator Yitzhak Molcho and the American Envoy for Israeli-Palestinian negotiations Martin Indyk after a meeting with President Obama on Tuesday. WASHINGTON - Secretary of State John Kerry said on Tuesday that Israeli and Palestinian negotiators would convene again in the Middle East within two weeks and that their goal would be to work out a comprehensive peace agreement within nine months. Mr. Kerry described the talks here on Monday and Tuesday as constructive, and said they had involved three-way discussions that included the United States, as well as direct discussions between the Israelis and the Palestinians. He said that the next meeting would mark the beginning of formal negotiations on the major issues, and that it would take place in Israel or the West Bank. "The parties have agreed to remain engaged in sustained, continuous and substantive negotiations on the core issues," said Mr. Kerry, who was flanked by Tzipi Livni, Israel's justice minister, and Saeb Erekat, the chief Palestinian negotiator. "Our objective will be to achieve a final status agreement over the course of the next nine months," Mr. Kerry said. We all understand the goal we are working towards: two states living side by side in peace and security. Earlier in the day, Mr. Kerry and the Israeli and Palestinian negotiators went to the White House to meet with President Obama and Vice President Joseph R. Biden Jr. Mr. Kerry said he was well aware that many experts and former officials thought that in seeking an agreement he was taking on an impossible mission. "I know that the path is difficult," he said. There is no shortage of passionate skeptics. But Mr. Kerry said that he thought a peace agreement was possible, and that both sides owed it to future generations to try. Martin S. Indyk, Mr. Kerry's envoy to the talks, is expected to be present when the two sides next meet. "When somebody tells you that Israelis and Palestinians cannot find common ground," Mr. Kerry said, "don't believe them."