(CNN) - President Barack Obama linked the man behind a botched Christmas Day airline bombing to an al Qaeda affiliate based in Yemen on Saturday.
The president pledged that everyone involved in the attack would be held accountable. He also highlighted his administration's attempts to crack down on extremist enclaves in Yemen, and reiterated his longstanding promise to "disrupt, dismantle and defeat" al Qaeda.
Obama has been criticized by some political opponents for not responding more aggressively to a botched December 25 attempt to blow up a Northwest Airlines passenger jet en route from Amsterdam, Netherlands, to Detroit, Michigan.
Authorities say 23-year-old Umar Farouk AbdulMutallab tried to ignite explosives smuggled aboard the plane in his underwear. Obama confirmed Saturday that AbdulMutallab recently traveled to Yemen and that "it appears that he joined an affiliate of al Qaeda."
The group "al Qaeda in the Arabian Peninsula" apparently trained AbdulMutallab, "equipped him with ... explosives and directed him to attack that plane headed for America," Obama said.
"This is not the first time this group has targeted us," Obama noted. Recently, he said, "they have bombed Yemeni government facilities and Western hotels, restaurants and embassies - including our embassy in 2008."
"I've made it a priority to strengthen our partnership with the Yemeni government - training and equipping their security forces, sharing intelligence and working with them to strike al Qaeda terrorists," he said.
Obama promised that "all those involved in the attempted act of terrorism on Christmas must know - you too will be held to account," Obama said in his weekly address.
"Our nation is at war against a far-reaching network of violence and hatred, and ... we will do whatever it takes to defeat them and defend our country."
Obama, currently on vacation with his family in Hawaii, spoke with Homeland Security Assistant John Brennan on Thursday to review preliminary assessments of the federal government's inability to prevent the Christmas Day attack.
AbdulMutallab had a valid, two-year multiple-entry visa into the United States - despite the fact that his father had twice spoken to at least one representative of the CIA at the U.S. Embassy in Nigeria about his son's increasingly extremist views.
A report detailing that information was prepared but not circulated outside the agency, a reliable source told CNN. Had that information been shared, AbdulMutallab might have been denied access to the flight, the source said.
The State Department announced Thursday it was directing American embassies around the world to include information on whether a person has a U.S. visa when they send special cables to Washington containing information on potentially suspicious individuals.
Obama also recently spoke with Homeland Security Secretary Janet Napolitano to receive an update on a federal review of "detection capabilities and ... enhanced security measures" put in place since the attempted bombing.
A new Transportation Security Administration directive requires airlines to physically pat down all passengers boarding planes bound for the United States and inspect their carry-on bags.
The directive also gives airlines the discretion to take other measures to prevent people from secretly assembling or igniting bombs on aircraft. Those measures include prohibiting people from keeping pillows or blankets on their laps during the final hour of a flight.