Mr. Blair, in testimony before the Senate Homeland Security and Governmental Affairs Committee, revealed a previously undisclosed disagreement among the Obama administration's top officials over the handling of the Nigerian who is accused of attempting to blow up Northwest Airlines Flight 253.

The intelligence chief said Umar Farouk Abdulmutallab should have been questioned by the High-Value Detainee Interrogation Group, or HIG, a special panel established by President Obama.

"We did not invoke the HIG in this case. We should have. Frankly, we were thinking more of overseas people. And, you know … that's what we will do now. And so we need to make those decisions more carefully," Mr. Blair told Sen. Susan Collins, Maine Republican and ranking member of the Homeland Security Committee.

Mr. Blair later issued a statement saying his remarks had been misconstrued. "The FBI interrogated Umar Farouk Abdulmutallab when they took him into custody," he said. "They received important intelligence at that time, drawing on the FBI's expertise in interrogation that will be available in the HIG once it is fully operational."

The HIG was mandated in August to question terrorism suspects apprehended overseas in counterterrorism operations. It was a result of an executive order Mr. Obama issued in January 2009 that compelled all interrogations to adhere to the practices enumerated in the Army Field Manual.

The practical effect of the order was to turn over interrogation responsibilities from the CIA, which used classified techniques, to the FBI, which has more experience in preparing evidence for civilian trials.

"That unit was created exactly for this purpose," Mr. Blair added. "To make a decision on whether a certain person who's detained should be treated as a case for federal prosecution, or for some of the other means."

When Mr. Blair was asked more directly whether he agreed with the decision to put Mr. Abdulmutallab on trial, he declined to answer.

The White House review of the failed Christmas Day terrorist plot was made public earlier this month by John Brennan. Mr. Obama's top adviser on homeland security and counterterrorism disclosed a string of security breakdowns, including a failure to share intelligence, a failure to revoke Mr. Abdulmutallab's U.S. visa and issues related to a counterterrorism watch list designed to block terrorists from entering the country.

"It appears to me that we lost an opportunity to secure some valuable intelligence information, and that the process that Director Blair described should have been implemented in this case," Ms. Collins said.

Sen. Christopher S. Bond, Missouri Republican and vice chairman of the Senate Select Committee on Intelligence, said the administration's intelligence officials "fumbled the Christmas Day terrorist case."

"That this administration chose to shut out our top intelligence officials and forgo collecting potentially lifesaving intelligence is a dangerous sign," Mr. Bond said in a statement.

Mr. Abdulmutallab is accused of trying to ignite a military-grade explosive known as PETN that was sewn into his underwear on the Northwest flight from Amsterdam to Detroit on Dec. 25.

The plot failed, and FBI agents apprehended Mr. Abdulmutallab in Detroit. He was questioned for at least two hours before agents read him his Miranda rights, which allowed him to have an attorney before answering further questions.

The White House has defended its decision to try Mr. Abdulmutallab in federal court. The decision appears in line with plans to send Khalid Shaikh Mohammed, the self-proclaimed mastermind of the Sept. 11, 2001, attacks, to face trial in federal court in New York.

When asked about the terrorism scare, Homeland Security Secretary Janet Napolitano told ABC News on Dec. 27 that "the system worked," and noted the response of federal authorities and the vigilance of the passengers who helped apprehend Mr. Abdulmutallab. Amid widespread public criticism, she subsequently corrected the remark.

At the Senate hearing Wednesday, Ms. Napolitano, Mr. Blair and Michael Leiter, director of the National Counterterrorism Center (NCTC), all testified that they were not consulted when an FBI special agent and the Justice Department decided to try Mr. Abdulmutallab in a civilian court.

Sen. John McCain, Arizona Republican, said the decision to try Mr. Abdulmutallab in federal court was a "terrible, terrible mistake."

At a separate hearing before the Senate Judiciary Committee, FBI Director Robert S. Mueller III said FBI agents on the ground made the decision to read Mr. Abdulmutallab his rights and allow him to have an attorney.

"It happened so fast that there was no time, really, at that point, where the transfer was made very quickly, given the moving circumstances, to determine whether alternative arrests could or should be made," Mr. Mueller said.

When asked why the NCTC failed to put Mr. Abdulmutallab on the proper no-fly lists, Mr. Blair said security analysts had been pressured in the past to reduce the no-fly lists and not to add new names.

"As you read through the guidance given to analysts that they were expected to cast a very fishy eye on the inclusion of lots more — lots more names," Mr. Blair said. "And the pressure was in the other direction. Shame on us for giving into that pressure."