PAHRUMP, Nevada (AP) — Republican presidential candidate Ben Carson is backing away from his Monday claim that he saw American Muslims celebrating the Sept. 11 attacks.

A spokesman for the retired neurosurgeon said Carson "does not stand behind" his statement to reporters hours earlier that he saw news reports of Muslims in New Jersey cheering the 2001 terrorist attacks. Republican rival Donald Trump has repeatedly made such claims in recent days, despite strong pushback from local officials.

"He does not believe Muslim Americans in New Jersey were celebrating the fall of the Twin Towers," Carson spokesman Doug Watts said. "Rather he recalls the ample news footage of crowds in the Middle East celebrating the tragic events of 9/11."

National security has become a focus in the presidential race over the last week after terrorists launched a series of deadly attacks in Paris.

Campaigning about an hour west of Las Vegas, Carson said that not only mosques, but schools, supermarkets, car repair shops and "any place where radicalization is going on" should be monitored in light of terrorist threats.

"I would say we use our intelligence and we monitor anything: our mosques, a church, a museum, a supermarket," he said, later adding that monitoring would come after multiple reports or indications of radical activity. "We live in a very different time right now."

Carson said he had seen footage of American Muslims cheering the Sept. 11 attacks, with reporters specifically asking about New Jersey. Hours later, Watts issued a written statement that Carson was citing news reports of Muslims cheering overseas.

"He found their jubilation inappropriate and disturbing, but did not and does not consider it representative of the Muslim American population or the Muslim population at-large," Watts said.

As for surveillance, Carson wouldn't elaborate on what increased monitoring would entail. He said he wasn't concerned about violating a person's right to privacy.

"The thing that will destroy our country is if we're overly concerned with violating someone's sensibilities while we allow blatant activity to occur that would violate all of our sensibilities," he said.