Washington (CNN) -- News of 12 terror-related arrests in Britain sped across the 24/7 cycle Monday. But the U.S. director of national intelligence, James R. Clapper Jr., somehow missed it.
In an interview that aired Tuesday but was taped on Monday, ABC's Diane Sawyer chatted with Clapper, Homeland Security chief Janet Napolitano, and John Brennan, the president's assistant for homeland security and counterterrorism.
She asked Clapper about the incident.
"First of all, London," Sawyer said. "How serious is it? Any implication that it was coming here? ... Director Clapper?"
Clapper was initially bewildered and Brennan jumped in to acknowledge the arrests.
Sawyer said to Clapper she was "a little surprised" that he "didn't know about London."
He replied "I'm sorry, I didn't."
His spokeswoman, Jamie Smith, on Wednesday said Clapper hadn't been briefed about the arrests, but should have been.
"Steps have been taken to ensure that he is (briefed) in the future," she said in a statement. "The intelligence community as a whole was fully aware of this development and tracking it closely."
Smith said Clapper hadn't been "immediately briefed" because the event "didn't appear to have a homeland nexus and there was no immediate action by the DNI required."
She also said the "DNI was working throughout the day on important intelligence matters, including monitoring military and political developments on the Korean Peninsula, providing answers to questions concerning the ratification of the START nuclear treaty, and other classified issues."
Monday's operation, led by the the British intelligence service, MI5, resulted in arrests of suspects ranging in age from 17 to 28 in the cities of London, Stoke and Birmingham, England, as well as Cardiff, Wales. A senior UK official not authorized to speak on the record said Monday that the suspects were arrested on suspicion of "preparation or instigation of an act of terrorism in the UK," but he also said the suspects were "aspirational" rather than equipped and "ready to go."
Brennan on Wednesday told reporters that Clapper should have been briefed by his staff, but he defended him for dealing with the intelligence issues President Barack Obama expects him to focus on.
"And I know there was breathless attention by the media about these arrests and it was constantly on the news networks. I am glad that Jim Clapper is not sitting in front of the TV 24 hours a day and monitoring what is coming out of the media," Brennan said.