Republican presidential frontrunner Donald Trump raised some eyebrows over the weekend when he claimed he saw “thousands and thousands” of Arab-Americans cheering in Jersey City – across the Hudson River from Manhattan – when the Twin Towers collapsed on Sept. 11, 2001. And New Jersey Gov. Chris Christie says he doesn’t remember that happening.

“I don’t recall that. I don’t,” said Christie during a stop in New Hampshire on Sunday when asked about Trump’s characterization, which was first reported by NJ Advance Media. The governor, who is also seeking the GOP nomination, instead spoke about how he had family and friends who were in downtown Manhattan.

“I do not remember that. And so it’s not something that was part of my recollection. I think if it had happened, I would remember it. But, you know, there could be things I forget too. But I don’t remember that,” added Christie.

Trump first made the claim about the cheering at a rally in Birmingham, Alabama on Saturday, even though police said at the time that there was no evidence that that such an incident took place. Still, Trump repeated the claim on Sunday during an interview on ABC’s “This Week.”

“It did happen. I saw it. It was on television,” said the billionaire real estate mogul. “There were people that were cheering on the other side of New Jersey, where you have large Arab populations. They were cheering as the World Trade Center came down.”

The claim comes as Trump has zeroed in on Muslim-Americans following the recent terrorist attacks in Paris. Trump has said he wants surveillance of “certain mosques,” suggested a national database for U.S. Muslims, and said he would “absolutely” bring back waterboarding as an interrogation tactic.

Christie’s campaign provided audio of his remarks in New Hampshire, and a spokesperson insisted the governor was condemning Trump’s remarks. Still, Christie’s response to Trump’s claim was milder than that of other critics. Republican White House hopeful George Pataki, for example, tweeted “Not sure what luxury spider-hole @realDonaldTrump was hiding in on Sept11 but I saw Americans come together that day.”

Jersey City Mayor Steven Fulop, a Democrat, tweeted, “Either @realDonaldTrump has memory issues or willfully distorts the truth, either of which should be concerning for the Republican Party.”