Rudolph Giuliani, promoting Donald Trump's national security plan, said Monday that in the "eight years before (President Barack) Obama came along, we didn't have any successful radical Islamic terrorist attack in the United States." That's an apparent omission of the largest terror attack in United States history.

Giuliani was mayor of New York City on Sept. 11, 2001 and in the hours after the World Trade Center fell, while then-President George W. Bush was largely unseen, he became the face of American grief and determination. His brave and graceful performance in the weeks after the towers' collapse earned him the nickname "America's mayor" and he was soon launched into national political stardom, his name synonymous with the response to the attacks. That made his comments Monday all the more puzzling.

"Under those eight years, before Obama came along, we didn't have any successful radical Islamic terrorist attack in the United States. They all started when Clinton and Obama got into office," Giuliani said ahead of Trump's speech on national security.

The eyebrow-raising comments, which were immediately lampooned on social media, were a far cry from Giuliani's usual speeches, which are often peppered with references to the resolve New Yorkers displayed after the attacks. In fact, his discussions of the attacks were so common that Vice President Joe Biden once said of him there were "only three things he mentions in a sentence: A noun, a verb and 9/11."

Jake Menges, a spokesman for the former mayor, told The Associated Press on Monday evening that Giuliani was referring to a lack of major attacks during the remainder of Bush's term.

Earlier in his speech the former mayor made several mentions to the 2001 attack.

"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," Giuliani said minutes before his apparent gaffe.

Though Giuliani governed the nation's largest city as a moderate Republican, who moved much further to the right when he welcomed Bush to New York for the 2004 Republican National Convention and as he mounted an ill-fated 2008 presidential bid. He has fashioned himself as a sharp critic of Obama as well as Hillary Clinton, whom Giuliani was to run against for the U.S. Senate in 2000 before bowing out after a cancer diagnosis.

But while Giuliani has never publicly blamed Bush for the 2001 attacks, Donald Trump on several occasions during this year's Republican primary made a point of saying that the attacks happened "during the reign of George Bush."

"You always have to look to the person at the top," Trump said in October. "Do I blame George Bush? I only say that he was the president at the time, and you know, you could say the buck stops here."

