Mayor Bill de Blasio denied smoking pot on Jan. 7, 2015. View Full Caption YouTube/NYC Mayor's Office

NEW YORK CITY — They're not the joint chiefs.

Mayor Bill de Blasio said that he and his wife, Chirlane McCray, haven't smoked marijuana while at Gracie Mansion.

During a press announcement Wednesday afternoon about the cellphone ban being lifted at public schools, de Blasio was asked if he and McCray had smoked "inside" the mayor's official residence.

"No," the mayor said as onlookers, including Schools Chancellor Carmen Fariña, smiled.

"I haven't smoked marijuana since I was at NYU," said the grinning mayor at the High School of Telecommunication Arts and Technology in Bay Ridge.

The question referenced a recent segment on Fox News, former NYPD officer and commentator Bo Dietl suggested that de Blasio was frequently late because he was smoking marijuana.

De Blasio was also asked in November if he smoked marijuana, and gave the same response.

"I think this job is truly 24/7, and you have to be alert at all times,” de Blasio said.