The regional organization's senior official in charge of Palestinian affairs, Mohammed Sobeih, called Gingrich's remarks "irresponsible and dangerous," reported the Telegraph:
"If an Arab or Palestinian official said a racist comment that was one-millionth of what this US candidate said, the world would have been in continuous uproar.
"If these comments were made for political gains, then this is an even bigger disaster. But it appears that this is a cheap attempt to get more votes in an election."
Speaking in an interview with the Jewish Channel Friday, Gingrich said there had never been a Palestinian state but instead "an invented Palestinian people, who are in fact Arabs."
He then defended the comments during a Republican debate the next day, saying: "Somebody ought to have the courage to tell the truth. These people are terrorists."
The statement drew applause from the audience in Des Moines, Iowa, the Associated Press said.
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Gingrich's spokesman, R.C. Hammond, later issued a statement stressing that the presidential hopeful supported a peace agreement between Israel and the Palestinians, which would necessarily include the creation of a Palestinian state.
A spokesman for the Israeli government, Mark Regev, refused to comment on the controversy since it was part of an "internal American political campaign."
But some hardline politicians "on the margins of the Israeli consensus" agreed with Gingrich's position, the AP said. Danny Denon, deputy speaker of Israel's parliament, said "most of the Jewish people, not just in Israel" share Gingrich's view.
Israel's Prime Minister Benjamin Netanyahu has officially recognized the Palestinian people.
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