NEW YORK (CBSNewYork) — Former New York Mayor Rudy Giuliani had quite the gaffe while speaking before Donald Trump’s foreign policy speech in Ohio on Monday.

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Giuliani, who was the mayor during the 9/11 terror attacks, said that there were no successful terrorist attacks in the United States in the eight years before President Barack Obama came into office.

“By the way, under those eight years before Obama came along, we didn’t have any successful radical Islamic terrorist attacks in the United States. They all started when Clinton and Obama got into office,” Giuliani said.

Obama took the oath of office in 2009.

However, right  before the gaffe, Giuliani was talking about the Sept. 11 terror attacks.

“Remember, we didn’t start this war, they did. We don’t want this war, they do. And they didn’t start it even in 2001, they attacked the World Trade Center in 1993 and they attacked it under the ideology of radical Islamic extremism to create a caliphate, to destroy the infidels – Christians, Jews, non-believing Muslims from their point of view and other people,” the former mayor said.

Giuliani even described Republican vice presidential nominee Mike Pence visiting Ground Zero while he was a member of Congress.

“Mike Pence understands this, from his time both on the Foreign Affairs Committee, from his very, very timely visit which I remember to Ground Zero when we were in desperate need of help, he was there, and from his work on the Judiciary Committee in helping to fashion the Patriot Act,” he said.

Twitter to Giuliani to task for the slight.

More than 3,000 people died in the Sept. 11 terror attacks.