DES MOINES, Iowa (AP) ― Republican presidential hopeful Newt Gingrich said he supports a peace agreement between Israel and the Palestinians that includes two separate states, but he did not step back Saturday from his assertion that Palestinians are an “invented” people, an incendiary comment that infuriated one side in the Mideast peace process.

The burden to show a willingness to reach a peace accord with the Israelis lies squarely with the Palestinians, he said.

“When the president keeps talking about a peace process while Hamas keeps firing missiles into Israel, if we had a country next to us firing missiles, how eager would we be to sit down and negotiate?” Gingrich told a veterans forum in Des Moines, before participating in a nationally televised debate with six other Republican candidates vying for the presidential nomination.

Palestinian officials reacted furiously on Saturday to Gingrich’s assertion, accusing the Republican presidential hopeful of incitement and staging a “cheap stunt” to court the Jewish vote.

The remarks struck at the heart of Palestinian sensitivities about the righteousness of their struggle for an independent state and put Gingrich at odds not only with the international community but with all but an extremist fringe in Israel. Mainstream Israelis, including Prime Minister Benjamin Netanyahu, support the idea of an independent Palestine alongside Israel as part of a final peace agreement.

As Gingrich has risen to lead in national and early-voting-state polls, he has come under criticism from his party rivals for making inflammatory statements. The Palestinian comments intensified that scrutiny with less than four weeks until Iowa’s precinct caucuses on Jan. 3 kick off the nominating contests to choose a challenger to President Barack Obama.

In footage released Friday, the former House speaker told the Jewish Channel, a U.S. cable TV network, that the Palestinians were an “invented people.”

“Remember, there was no Palestine as a state ― (it was) part of the Ottoman Empire. I think we have an invented Palestinian people who are in fact Arabs and historically part of the Arab community and they had the chance to go many places,” Gingrich said according to a video excerpt posted online.

Gingrich sought to clarify his position later Saturday, saying in Iowa that he supports a negotiated peace agreement between Israel and the Palestinians, including a Palestinian state.

In a statement, Gingrich spokesman R.C. Hammond said that “to understand what is being proposed and negotiated you have to understand decades of complex history ― which is exactly what Gingrich was referencing.”

“Newt Gingrich supports a negotiated peace agreement between Israel and the Palestinians, which will necessarily include agreement between Israel and the Palestinians over the borders of a Palestinian state,” Hammond said in the statement.

Those latest comments appeared unlikely to calm the uproar among Palestinian officials.

Palestinian Prime Minister Salam Fayyad demanded that Gingrich “review history.”

“From the beginning, our people have been determined to stay on their land,” Fayyad said in comments reported by the Palestinian news agency Wafa. “This, certainly, is denying historical truths.”

Saeb Erekat, the chief Palestinian negotiator, accused Gingrich of incitement. “Mark my words ... these statements of Gingrich’s will be the ammunitions and weapons of the bin Ladens and the extremists for a long, long time,” Erekat told CNN.

The Palestinians have never had an independent state of their own. The region was ruled by the Ottomans for several centuries, and when the Ottoman Empire collapsed after World War I, the British took control of the area. It was known as the British Mandate for Palestine, and Muslims, Christians and Jews living there were all referred to as Palestinians.

Democratic Sen. Carl Levin of Michigan sharply criticized Gingrich’s comments as cynical attempts to curry support with Jewish voters and unhelpful to the peace process.

“The vast majority of American Jews (including this one) and the Israeli Government itself are committed to a two-state solution in which Israelis and Palestinians live side-by-side as neighbors and in peace,” Levin said in a statement. “Gingrich offered no solutions ― just a can of gasoline and a match.”

And while Gingrich sought to reassert his openness to a two-state solution, which has been the position of Republican and Democratic administrations, he said it was appropriate to discuss the history of the region.

“We have a challenge in the Middle East, and this is one where we’re going to have a national debate that’s going to be very difficult and that people are going to find at times very frustrating,” he told about 100 veterans in a theater near Drake University a few hours before the debate. “We can’t have an honest conversation about what’s going on in the Middle East, we can’t even discuss what the roots of the problem are.”

After the Arabs rejected an international plan calling for the establishment of Jewish and Arab states, part of the land became the state of Israel. During the 1948 war surrounding the Jewish state’s creation, hundreds of thousands of Palestinians fled or were forced to flee their homes.

Just as Israeli identity was forged after a long nationalist struggle staged by Zionist Jews for a state of their own, the identity of Palestinian Arabs was also hewn by their own decades-long struggle over the same land.

Shortly after taking office in 2009, Netanyahu endorsed the establishment of a Palestinian state, abandoning his Likud Party’s traditional opposition to the idea. More moderate Israeli leaders have sought a peace deal with the Palestinians for the past two decades.

Palestinian legislator Hanan Ashrawi, a top official in the Palestine Liberation Organization, said that Gingrich was seeking a “cheap way” to win Jewish and pro-Israel voters in next year’s election.

Some Israeli politicians on the margins of the Israeli consensus welcomed Gingrich’s stance. Danny Danon, deputy speaker of Israel’s parliament, and a minority voice among his hawkish Likud party, said Gingrich “understands very well the reality we live in the Middle East” and said his statement on the Palestinians is shared by “most of the Jewish people, not just in Israel.”