Homeland Security Secretary Janet Napolitano conceded on Monday that an attempted bombing aboard an international flight landing in Detroit constituted a security failure.

Napolitano initially stressed "the system worked" during an interview on CNN this weekend, noting the crew of Flight 253 "took appropriate action" to address the terrorist plot as it unfolded. But her remarks were met with instant criticism, prompting the Homeland Security chief to clarify their meaning during a round of media appearances on Monday morning.


“Our system did not work in this instance," Napolitano told The Today Show. "I think the comment is being taken out of context."

“No one is happy or satisfied with that. An extensive review is under way,” she added.

On each of the networks, Napolitano stressed that law enforcement officials were still investigating how Umar Farouk Abdulmutallab, the alleged attempted bomber, boarded the plane with explosive materials. She also assured that the federal government was doing everything in its power to prevent another, similar incident from occuring.

"This is an ever-changing environment that we're dealing with. We can't just be static," Napolitano told ABC. "And so we will take this incident. There will be lessons learned that we deal with and fix. And that process is ongoing. And as you might imagine, it's ongoing at lightning speed."

Republican lawmakers such as Rep. Pete Hoekstra (Mich.) have criticized the Obama administration's handling of the terrorist plot. Some charge the president was wrong to remain silent as news broke on Christmas Day, while others have used the attempted bombing as reason to renew their calls for increased security at domestic airpoints.

Still others fault the administration for lax anti-terrorism efforts writ large, while Hoekstra has charged the White House with "stonewalling" congressional inquiries.

The White House announced Monday the president would address last week's incident from a military base in Hawaii, where he has vacationed since Christmas.