Saying he wanted to "dispel a myth," Chertoff also said at a news conference in Washington there are only 2,500 names on the "no-fly" list put in place after the Sept. 11, 2001, terrorist attacks.
"I'm constantly reading in the paper that there are hundreds of thousands of people on the no-fly list or the selectee list, maybe as many as a million people on the selectee list or the no-fly list," Chertoff said. "So I'm here to tell you that that is simply false.
"The truth is there are fewer than 16,000 ... unique individuals who are selectees in TSA's database. Most of these people are not even American citizens. And being a selectee ... means you're going to get a little bit of extra scrutiny, but it does not bar you from getting on the airplane.
"Second, the actual number of people who are on the no-fly list, meaning that they are barred from flying under any circumstance, is less than 2,500, and only 10 percent of those are American citizens."
The American Civil Liberties Union has pegged the number of names on the lists at more than 1 million. The FBI said in August there were about 400,000 people on its terrorist screening list, with only about 5 percent U.S. citizens.