Speaking on ABC's "This Week," Kelly said: "I can tell you, in New York City, we have a task force in our intelligence division that looks at white supremacist/anti-government groups and individuals.
"In fact, just a few days before the [July 22] Norway massacre, we had a teleconference with our century partners -- this is 100 law enforcement agencies in the northeast quadrant of the country -- and that was the specific subject."
"It is an ongoing issue that law enforcement has to continue to focus on, and I believe we are," Kelly added.
"We follow certain individuals on the Internet," he said. "They put out their feelings quite clearly. A lot of them are careful about not advocating violence.
"For instance, the individual in Norway, although he had a lot of Internet activity, did not advocate violence. He put his manifesto on the Internet six hours before he started the attacks. They're somewhat careful about advocating violence."