Meanwhile, Mr. Obama's top counterterrorism adviser said there was "no smoking gun" in the attempted bombing of a U.S. airliner on Christmas Day, despite a slew of missed red flags, including the facts that the bomber paid cash for his ticket and checked in without luggage.
"In this one instance, the system didn't work. There were some human errors. There were some lapses. We need to strengthen it. But day in and day out, the successes are there," said John Brennan, the assistant to the president for homeland security and counterterrorism.
Nine days after the failed bombing, Democrats and Republicans continued to stake out their political territory on terrorism, with each side keeping an eye on the midterm elections later this year. Republicans charged that Mr. Obama has given national security short shrift as he has focused on domestic issues.
"Heaven's sake, if you're in this huge health care fight and worried about the economy and global warming and all that sort of thing," said Thomas Kean, a former Republican governor of New Jersey and former chairman of the Sept. 11 commission. "That's what they were concentrating on. And I think they weren't giving this enough attention. It's understandable, but it's not acceptable."
Mr. Kean said the intelligence community is taking its cue from the president, and the whole system breaks down if Mr. Obama fails to support his team.
"They need support; they need coordination. The president needs to supply the leadership. And no matter what else is going on, this has always got to be No. 1," he said on CNN's "State of the Union."
Frances Townsend, who served as homeland security adviser to President George W. Bush, said on the same CNN show that Mr. Obama received a briefing about a Christmas threat before departing for Hawaii, but did not spur his intelligence team to vigilance.
"The entire federal bureaucracy takes its cue from the White House in terms of priorities. The president has been very involved in his domestic policy agenda. And that can't be helpful to the intelligence community, to the law enforcement community and those who really need to fight for his time and attention now," she said.
Sen. Susan Collins, Maine Republican and ranking member of the Senate Homeland Security and Governmental Affairs Committee, said federal authorities failed twice to prevent the attempt to blow up a U.S. airliner over Detroit on Christmas Day.
Ms. Collins said authorities failed to act on a credible report from the suspect's father that should have caused the State Department to revoke his visa.
But Mr. Brennan said, "There was no single piece of intelligence that said, 'This guy is going to get on a plane.'"
Mr. Brennan said there were "a number of streams of information" and "little snippets" from intelligence channels.
"But there was nothing that brought it all together," said Mr. Brennan, who made appearances on the Sunday TV news shows: ABC's "This Week," NBC's "Meet the Press," CNN's "State of the Union" and "Fox News Sunday."
Still, he said, much more should have been done.
"What we need to do as an intelligence community, as a government, is be able to bring those disparate bits and pieces of information together so we prevent Mr. Abdulmutallab from getting on the plane," Mr. Brennan said.
A 23-year-old Nigerian, Umar Farouk Abdulmutallab, is charged with assembling an explosive device, including 80 grams of Pentrite, or PETN, in the aircraft toilet of a Detroit-bound Northwest flight. He failed to detonate the device with a syringe of chemicals. Passengers then intervened and the plot was foiled.
Mr. Abdulmutallab, who held a U.S. visa, has been linked to a branch of al-Qaida in Yemen. Last month, his father, a prominent retired banker, went to the U.S. Embassy to report that his son had expressed radical views and was worried about his plans. The embassy alerted Washington and the son's name was logged into a database of more than 500,000 people, but he was not put on the "no-fly" list of 4,000 people or another list of nearly 15,000 people who are stopped for additional screening when they try to board a plane.
In addition, the National Security Agency intercepted conversations among leaders of al-Qaida in Yemen four months ago laying out a plan to use a Nigerian man for an imminent terrorist attack.
Mr. Brennan said an active threat from al-Qaida led the United States to close its embassy in Yemen. He said the U.S. does not plan to open a new front in Yemen in the global fight against terrorism.
"We're not going to take any chances" with the lives of American diplomats and others at the embassy in Yemen's capital, Mr. Brennan said. "There are indications al-Qaida is planning to carry out an attack against a target inside of San'a, possibly our embassy."
Mr. Brennan is leading a White House review of the incident. Mr. Obama has said there was a "systemic failure" to prevent the attack, which he said was instigated by an affiliate in Yemen of the al-Qaida terrorist network.
Mr. Obama has ordered a thorough look at the shortcomings that permitted the plot, and he has summoned homeland security officials to meet with him in the White House Situation Room on Tuesday.
Mr. Brennan and other top officials have come under fire because of the oversights. He stood by Homeland Security Secretary Janet Napolitano, although he acknowledged that she has "taken some hits" for saying that the airline security system had worked.
It didn't, and she clarified her remarks to say that she meant the system worked only after the attack was foiled, Mr. Brennan said.
He said the situation was not like that before the attacks of Sept. 11, 2001, when intelligence agencies failed to share tips and information that might have uncovered the plot. "There's no evidence whatsoever that any agency or department was reluctant to share" information, he said.
Mr. Brennan said the threat against Americans and Westerners would not ease until Yemen's government got a better handle on the threat from terrorists inside the country. He estimated that several hundred members of al-Qaida are in Yemen. "We are very concerned about al-Qaida's continued growth there," he said.
Mr. Brennan also said he is disappointed with remarks by former Vice President Dick Cheney, who last week accused Mr. Obama of "trying to pretend" that the U.S. is not at war with terrorists.
"Either the vice president is willfully mischaracterizing this president's position both in terms of the language he uses and the actions he's taken [or] he's ignorant of the facts," he said. "And in either case it doesn't speak well of what the vice president is doing . . . I don't care what Republicans or Democrats say out there. We need to continue to prosecute this war because al-Qaida the organization needs to be destroyed."
Republicans also have criticized the administration for the planned closure of the detention facility at U.S. Naval Base Guantanamo Bay, Cuba, but the recent attempted attack has swayed some Democrats, who now say the U.S. should reconsider whether to repatriate suspected terrorists from Yemen.
Rep. Jane Harman, California Democrat and a member of the Homeland Security Committee, said Sunday that officials should review the transfers. She does support plans to close the prison and open one in Illinois for terrorism suspects.
"I think it is a bad time to send the 90 or so Yemenis back to Yemen," Mrs. Harman said.
Sen. Joe Lieberman, a Connecticut independent who has opposed closing Guantanamo, said transferring any of the Yemeni detainees back home would be irresponsible.
"We know from past experience that some of them will be back in the fight against us," Mr. Lieberman said.
Also on Sunday, Mr. Brennan said the White House's nominee to head the Transportation Security Administration is well qualified and should be confirmed promptly. He said Erroll Southers, a former FBI agent, has satisfied the great majority of senators about misstatements he made regarding a personal matter from two decades ago.
Sen. Jim DeMint, a South Carolina Republican who is blocking the nomination, said he wants assurances that Mr. Southers will not advocate collective bargaining for TSA workers.