WASHINGTON -- President Barack Obama sought to allay concern in the Jewish community Sunday by telling America's largest pro-Israel lobby that he had said "publicly what has long been acknowledged privately."

Obama had spoken on U.S. policy toward the Middle East Thursday and addressed the ongoing Israeli-Palestinian conflict. He called for a lasting peace that would begin with a Palestinian state based on 1967 borders.

Speaking to the American Israel Public Affairs Committee Sunday, Obama said that while U.S. support for Israel remains "ironclad," "we cannot afford to wait another decade, or another two decades, or another three decades, to achieve peace. The world is moving too fast."

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Even as Israel approved more Jewish settlements on the occupied West Bank, Obama told a mostly polite audience that Israel faced further isolation if bold steps were not taken to head off a United Nations General Assembly vote on Palestinian statehood in September.

"This is not idealism or naivete," Obama said. "It's a hard-headed recognition that a genuine peace is the only path that will ultimately provide for a peaceful Palestine as the homeland of the Palestinian people and a Jewish state of Israel as the homeland of the Jewish people."

"The march to isolate Israel internationally -- and the impulse of the Palestinians to abandon negotiations -- will continue to gain momentum in the absence of a credible peace process and alternative," he added, noting that in order to have leverage with the Palestinians and the international community, "the basis for negotiations has to hold out the prospect of success."

Obama acknowledged that his words were not warmly welcomed by many in Israel or among right-leaning Jews in America, but he went to great lengths to explain why his emphasis on 1967 borders was "misrepresented" and his words were neither controversial nor new.

"There was nothing particularly original in my proposal; this basic framework for negotiations has long been the basis for discussions among the parties, including previous U.S. Administrations," he said, noting the same ideas had been put forth by President Bill Clinton.

While many headlines had focused on his call for 1967 lines, he said, they downplayed the caveat of mutually agreed land swaps.

This, he said, meant that Israel and the Palestinians would negotiate a border that is different from the one that existed on June 4, 1967, when the Six Day War began and Israel occupied the West Bank, Gaza and the Golan Heights.

"It is a well known formula to all who have worked on this issue for a generation. It allows the parties themselves to account for the changes that have taken place over the last 44 years, including the new demographic realities on the ground and the needs of both sides," Obama said. "The ultimate goal is two states for two peoples. Israel as a Jewish state and the homeland for the Jewish people, and the state of Palestine as the homeland for the Palestinian people; each state enjoying self-determination, mutual recognition, and peace."

Obama prefaced his explanation with a list of ways his administration had continued America's staunch support of Israel. He acknowledged Israel was the "ancient homeland" of the Jewish people. He also noted that Israel faced attack from Hamas rockets launched from Gaza and that a recent agreement between Hamas and the Palestinian political party Fatah "poses an enormous obstacle to peace." And in a reference to Iranian President Mahmoud Ahmadinejad, Obama said he understood "the existential fear of Israelis when a modern dictator seeks nuclear weapons and threatens to wipe Israel off the map."

He also highlighted U.S. military aid to Israel, such as the new Iron Dome anti-rocket system and sanctions on Iran and its pursuit of nuclear weapons.

"In both word and deed, we have been unwavering in our support of Israel's security," Obama said. "And it is precisely because of our commitment to Israel's long-term security that we have worked to advance peace between Israelis and Palestinians."

"We must acknowledge that failure is not an option," he said. "The status quo is unsustainable."

Republicans have reacted strongly to the Obama's Thursday speech. GOP presidential hopeful Mitt Romney accused the president of "throwing Israel under the bus."

Obama strayed from his prepared remarks to address the criticism, noting he had "generated some controversy over the past few days." He said, "The easy thing to do, particularly for a president preparing for reelection, is to avoid any controversy," and said he didn't need former White House advisers Rahm Emanuel or David Axelrod to tell him that.

Jennifer Laslo Mizrahi, president of The Israel Project, a pro-Israel public affairs group, said Obama had told the people in the room what they wanted to hear.

"Most Jews vote Democrat, but most supporters of Israel are not Jews," she said. "Jobs and the economy are still top issues but Israel is as much a part of American values and traditions as are hot dogs, apple pie and freedom."

Brad Bauman of the National Jewish Democratic Council said Republicans have sought to "manipulate the facts" to scare Jewish voters.

"The president's political enemies continue to do a disservice to our relationship with Israel by fear-mongering, spreading half-truths and allowing false statements to go uncorrected," he said. "They foment fear and conspiratorial thoughts within our community and drive media reports around the world which cast a doubt on the most significant and important truth about America's relationship with Israel: This president and the United States stands decidedly with Israel."

But Noam Neusner, a former speechwriter for George W. Bush and a Republican strategist, said Obama's AIPAC speech may have restated standing policy, but it surprised many of his Jewish supporters nonetheless. That surprise is not good news for the incumbent if he is "fighting for voters he normally can take for granted."

"They wanted to believe he was in their corner. That means his own people misjudged the speech," Neusner wrote in an email to The Huffington Post. "The Obama political team now needs to recover. Perhaps the AIPAC speech will help him, but a lot of damage has already been done."

Neusner tied the speech to the upcoming 2012 election, saying that while Obama "will still retain commanding majorities of typically liberal Jewish voters, the moderates in Florida, Ohio, Pennsylvania, Nevada and other key states will remember this. And the donor base -- a big deal to Obama and the entire party -- will definitely remember this."