The White House's top counterterrorism official on Thursday said he too was partly responsible for the intelligence lapses preceding the Flight 253 terror plot.

"I told the president today, I let him down," Deputy National Security Adviser John Brennan said during this afternoon's White House press briefing. "I told him I will do better; we will do better as a team."

Brennan has been under fire since the Christmas Day attack, in part for initially stressing there was no "smoking gun" suggesting suspect Umar Farouk Abdulmutallab intended to board and bomb the Detroit-bound plane.

However, a thorough analysis of pre-attack intelligence -- a summary of which was declassified this afternoon -- showed that the intelligence community did have some reason to believe al Qaeda terrorists planned to attack both U.S. interests and the domestic homeland, the president said during his speech today.

White House officials now seem to agree that the entire national security team shares responsibility for missing intelligence in advance of the Christmas Day attack.

But Brennan stressed this afternoon that the Flight 253 mishaps hardly alter the fact that the country's law enforcement and intelligence teams have done "stellar job" on every other occasion.

"It was in this one instance that we did not rise to that same level of competence and success," he said.