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He added, "We're going to be in an environment in this new world where so much is digitalized that both state and non-state actors are going to have the capacity to disrupt our lives in all sorts of ways. We have to do a much better job of guarding against that."
The president said he will "review" whether to put North Korea back on the state-sponsored terror list. "We look systematically at what's been done and based on those facts, we'll make those determinations in the future," said Obama.
In a year-end news conference Friday, Obama said Sony made a "mistake" by pulling a satirical film about North Korea after the attack.
"We cannot have a society in which some dictator someplace can start imposing censorship here in the United States," he said.
Some Republicans appearing on Sunday news shows were critical of Obama's overall response to the Sony hack.
"This was a nation-state attack on the United States and saying aloha and getting on an airplane, going to Hawaii is not the answer that really the world needs, let alone America," retiring Rep. Mike Rogers (R-Mich.), the outgoing chairman of the House Intelligence Committee, said in an interview on "Fox News Sunday." He was referring to Obama leaving Friday for a vacation.
Asked whether he believed the hack was an act of war, Rogers responded, "You can't necessarily say an act of war. We don't have good, clear policy guidance on what that means when it comes to cyberattacks."
On CNN's "State of the Union," Sen. John McCain (R-Ariz.) said, "The president does not understand that this is a manifestation of a new form of warfare."
Reflecting on his decision to normalize relations with Cuba, Obama told CNN, "For 50 years, we've tried to see if we can overthrow the regime through isolation. It hasn't worked. If we engage, we have the opportunity to influence the course of events at a time when there's going to be some generational change in that country. And I think we should seize it and I intend to do so."