"The reason that there's not peace between the Palestinians and Israel is because there is, in the leadership of the Palestinian people... Hamas and others who think like Hamas, who have as their intent the elimination of Israel," Romney said, addressing a key Republican debate in Florida.

"There are people that say, should we have a two-state solution? And the Israelis would be happy to have that. It's the Palestinians that don't want it," he said bluntly in the final debate before Florida's presidential primary next week.

Answering a question from a Palestinian-American in the audience, Romney also blamed the stalemate on Obama's insistence that the borders in place before the Six-Day War in 1967 should form the basis for talks.

"This president, I think he threw Israel under the bus with regards to defining the '67 borders as a starting point of negotiations," Romney said.

"I think he has time and time again shown distance from Israel and that's created in my view a greater sense of aggression on the part of the Palestinians."

In a rare moment of agreement with his rival, former House speaker Newt Gingrich defended his earlier controversial charges that the Palestinian people were invented.

"It was technically an invention of the late 1970s and clearly so, prior to that, they were Arabs. Many of them were Syrian, Lebanese or Egyptian or Jordanian," he said.

Gingrich lashed out at Palestinian militant rocket fire on Israel, saying such an act "looks like an act of war... the leadership of Hamas says, not a single Jew will remain. That's not a peace negotiation. This is war by another form."

He urged the Palestinian people to give up a core demand -- the right of return for refugees -- and urged Hamas to acknowledge Israel's right to exist.

"We give up the right to return and we recognize we're going to live side-by-side. Now let's live together to create mutual prosperity and you could dramatically improve the quality of life of every Palestinian. But the political leadership would never tolerate that," he charged.

Meanwhile, Obama's allies hit back with a Twitter message from the chairwoman of the Democratic National Committee, Debbie Wasserman Schultz.

"Romney's wrong. President believes peace must come between Israel and Palestine through direct negotiation between the two," she wrote.