HONOLULU - Talking publicly for the first time since a failed Christmas Day plot to blow up a U.S. airliner in flight, President Barack Obama called it on Monday "a serious reminder" of the need to adapt continually to the terror threat facing the United States.
Even as Obama vowed to use "every element of our national power" to keep Americans safe, word came that a U.S. State Department warning had failed to trigger an effort to revoke the alleged attacker's visa. Officials in Yemen confirmed that the suspect had been living in that country, where an al-Qaida-affiliated group quickly sought to take responsibility for his actions.
The incident prompted stiffer airport boarding measures and authorities warned holiday travellers to expect extra delays as they return home this week and beyond.
Umar Farouk Abdulmutallab, 23, charged with trying to destroy an aircraft, is being held at the federal prison in Milan, Michigan. A court hearing that had been scheduled for Monday to determine whether the government can get DNA from him was postponed until Jan. 8. No reason was given.
Calling Abdulmutallab's action an "attempted act of terrorism" Obama vowed to "do everything that we can to keep America safe" and declared: "The United States will more than simply strengthen our defences. We will continue to use every element of our national power to disrupt, to dismantle and defeat the violent extremists who threaten us."
Members of Congress, meanwhile, questioned how a man flagged as a possible terrorist managed to board a commercial flight into the United States carrying powerful explosives and nearly bring down the jetliner. Sen. Joe Lieberman, an independent from Connecticut, said Monday that the Senate Homeland Security and Governmental Affairs Committee that he chairs would hold hearings in January.
Meanwhile, al-Qaida in the Arabian Peninsula claimed responsibility for the thwarted attack as retaliation for a U.S. operation against the group in Yemen. Yemeni forces, helped by U.S. intelligence, carried out two airstrikes against al-Qaida operatives this month in the lawless country that is fast becoming a key front in the fight against terrorism. The second one was a day before Abdulmutallab attempted to bring down a Northwest Airlines flight as it prepared to land in Detroit.
Yemen has long been an al-Qaida stomping ground. But officials fear that deepening instability in the Middle Eastern nation may be giving new opportunity for the terror group to establish a base to train and plan for attacks on the West.
A statement posted on the Internet by al-Qaida in the Arabian Peninsula said Abdulmutallab co-ordinated with members of the group and used explosives manufactured by al-Qaida members.
Solving one mystery of Abdulmutallab's pre-Detroit path, the Yemeni Foreign Ministry said Monday that he was in Yemen from August until early December. He had received a visa to study Arabic in a school in San'a. Citing immigration authorities, the statement said Abdulmutallab had previously studied at the school, indicating it was not his first trip to Yemen.
Obama, on vacation in his birthplace of Hawaii, acknowledged the attack showed the need to increase the United States' defences. He detailed the pair of reviews that he has ordered to determine whether changes are needed in either the watchlist system or airport screening procedures.
"This was a serious reminder of the dangers that we face," he said. "It's absolutely critical that we learn from this incident."
Obama's remarks Monday were the first heard from him on the Christmas Day scare three days earlier.
Officials said that was deliberate, an effort by the White House to balance the need for the president to show concern but also not to unduly elevate a botched incident and thereby encourage other would-be attackers.
Back in Washington, federal officials met to review their layered system of watchlists and other procedures to examine how to avoid the type of lapses that led to the attack.
Abdulmutallab's family in Nigeria released a statement that said his father had contacted Nigerian security agencies two months ago. The statement says the father then approached foreign security agencies for "their assistance to find and return him home."
U.S. officials say that is how Abdulmutallab came to the attention of American intelligence, just last month, when the father, prominent Nigerian banker Alhaji Umar Mutallab, reported to the American Embassy in Abuja. A senior U.S. official said the father was worried that his son was in Yemen and "had fallen under the influence of religious extremists." The father did not mention any specific threat.
The interest raised by Abdulmatallab's father landed him among the about 550,000 names in the Terrorist Identities Datamart Environment database, known as TIDE, which is maintained by the U.S. National Counterterrorism Center. Other, smaller lists trigger additional airport screening or other restrictions, but intelligence officials say there was not enough information to move him into those categories.
Another potential lapse concerns Abdulmutallab's visa.
Britain had refused to grant him a student visa in May, but the United States made no apparent effort to revoke his U.S. tourist visa, issued in June 2008 and good for multiple entries over two years.
The embassy visit by Abdulmatallab's father triggered a Nov. 20 State Department cable from Lagos to all U.S. diplomatic missions and department headquarters in Washington. It also was shared with the interagency National Counter Terrorism Center, said State Department spokesman Ian Kelly.
The NCTC, which has responsibility if any visas are to be pulled because of terror considerations, then reviewed the information and found it "insufficient to determine whether his visa should be revoked," Kelly said.
Homeland Security Secretary Janet Napolitano also conceded Monday that the aviation security system failed, backtracking from a statement Sunday in which she said it worked.
Republican Rep. Pete Hoekstra joined his party's critics of that statement. "They just don't get it," said Hoekstra, the top Republican on the House intelligence committee. "The system didn't 'work' here." Hoekstra, who is running to become his state's governor, included his criticism in a campaign email that asked supporters for donations.
The White House said Obama's low-key response was carefully calibrated.
The plane had been on the ground in Detroit for two hours on Friday before officials first informed Obama. Advisers said they wanted to make sure they had complete and accurate information before going to the president but, even so, Obama's first briefing with national security and homeland security advisers lasted less than 15 minutes. Obama's motorcade was rolling toward the gym minutes afterward.
Two days later, when another flight from Amsterdam to Detroit came under suspicion, it was about 90 minutes after it landed before Obama was informed of what had been a false alarm.
Throughout the weekend, Obama has mixed vacation activities with crisis monitoring. He played golf on Saturday with friends and was playing basketball with aides when that second flight landed in Detroit on Sunday. He went from there to a beach and a gourmet restaurant dinner in the evening.
On Monday, he did not address the public until after a workout and a tennis game with his wife - and went golfing immediately afterward.
Associated Press writers Jennifer Loven, Matt Lee, Eileen Sullivan, Lolita Baldor and Devlin Barrett in Washington; Pamela Hess in New York; Ed White in Detroit; Jon Gambrell in Lagos, Nigeria; Donna Abu-Nasr in Riyadh, Saudi Arabia; and Mark Niesse in Kaneohe Bay, Hawaii, contributed to this report.