WASHINGTON -- U.S. President Barack Obama spoke publicly for the first time on December 28 about the attempt to blow up a U.S. airliner on Christmas Day, vowing that the United States "will not rest" until it finds everyone responsible for the attack.
"The suspect is now in custody and had been charged with attempting to destroy an aircraft," Obama said.
"And a full investigation has been launched into this attempted act of terrorism and we will not rest until we find all who were involved and hold them accountable."
Obama spoke to reporters from the island state of Hawaii, where he is spending the holidays with family and friends.
He used the opportunity to emphasize the continual threat he said America faces from its enemies.
"This was a serious reminder of the dangers that we face and the nature of those who threaten our homeland. Had the suspect succeeded in bringing down that plane it could have killed nearly 300 passengers and crew, innocent civilians preparing to celebrate the holidays with their families and friends," Obama said.
As Obama was speaking, reports surfaced that a warning from the U.S. State Department had failed to trigger an effort to revoke the alleged attacker's visa.
Officials in Yemen confirmed that the suspect, 23-year-old Nigerian Umar Farouk Abdulmutallab, had been living in that country, where an Al-Qaeda-affiliated group has claimed responsibility for his actions.
Al-Qaeda in the Arabian Peninsula claimed responsibility for the attack as retaliation for a U.S. operation against its operations in Yemen.
Yemeni forces, helped by U.S. intelligence, carried out two air strikes against Al-Qaeda operatives this month in lawless areas of the country, which in recent weeks has emerged as a primary origin of threats against the West.
A statement posted on the Internet by the group said Abdulmutallab had coordinated with members of the group and used explosives manufactured by Al-Qaeda members.
Obama has ordered a top to bottom review of U.S. airline screening measures, already among the toughest in the world.
One aspect of the review involves the U.S. "watch list" system, which the government has used since 2001 to identify known and suspected terrorists in an attempt to prevent their entry into the United States.
Another will examine all screening policies, technologies, and procedures related to air travel. Obama said the government is determined to find out "how the suspect was able to bring dangerous explosives aboard an aircraft and what additional steps [can be taken] to thwart future attacks."
Obama said he had also directed the White House national security team to "keep up the pressure on those who would attack" the United States.
He said even though investigators don't know the full picture of the Christmas Day attempted attack, "those who would slaughter innocent men, women and children must know that the United States will do more than simply strengthen our defenses."
And he vowed to use "every element of [the country's] national power to disrupt, to dismantle, and defeat the violent extremists who threaten [it]-- whether they are from Afghanistan or Pakistan, Yemen or Somalia, or anywhere where they are plotting attacks against the U.S. homeland."
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 U.S. intelligence agencies last month, when his father -- prominent Nigerian banker Alhaji Umar Mutallab -- reported to the U.S. 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 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.