What should we call North Korea's cyberattack on Sony?

President Obama declined to label the North Korean government's cyberattack on Sony Pictures Entertainment an "act of war" in an interview that aired Sunday, characterizing the hack instead as an "act of cyber vandalism" and drawing swift pushback from Republicans as a result.

"No, I don't think it was an act of war," the president told CNN about the cyber intrusion, which exposed a raft of embarrassing emails between producers and Sony executives and was blamed for scuttling a movie premiere. "I think it was an act of cyber vandalism that was very costly, very expensive. We take it very seriously. We will respond proportionately."

The White House has repeatedly emphasized the importance of a proportional response to the attack, suggesting the hackers could be interested in provoking an overreaction by the U.S.

"We have to treat it like we would treat, you know, the incidence of crime...in our countries," the president said in the interview on CNN.

Two of Mr. Obama's most dogged foreign policy critics in the Republican Party, however, took issue almost immediately with the president's characterization.

Sen. John McCain, R-Arizona, suggested Mr. Obama "does not understand" what the attack represents.

"When you are able to impose censorship on the world, and especially the United States of America, it's more than vandalism," McCain said on CNN. "It's a new form of warfare that we're involved in. And we need to react, and react vigorously, including re-imposing sanctions that were lifted under the Bush administration, including other actions that will squeeze them more economically."

Sen. Lindsey Graham, R-South Carolina, underscored the need for stiff retribution in an interview on CBS' "Face the Nation," warning that other rogue regimes might be emboldened if the U.S. pulls any punches in its response to North Korea.

"They attacked who we are," the senator said. "And when the president calls this an act of 'vandalism,' that just really bothers me greatly. It is an act of terrorism, and I hope he will respond forcefully."

At least one key Republican, though, was reluctant to label the hack an "act of war," though he reserved plenty of criticism for the president nonetheless.

"You can't necessarily say an act of war," Rep. Mike Rogers, R-Michigan, in an interview on Fox News. "We don't have good, clear policy guidance on what that means when it comes to cyberattacks."

Rogers labeled the hack a "nation-state attack on the United States," and he suggested the president was remiss in beginning his Christmas vacation in Hawaii so quickly after the FBI linked North Korea to the attack.

"Saying aloha and getting on an airplane going to Hawaii is not the answer really the world needs, let alone America," Rogers said.

An attorney for Sony Pictures said Sunday that he's not particularly concerned about how people decide to label the cyberattack, and that he's more focused on the need for a strong response.

"I'm not debating whether it ought to be called criminal vandalism, terrorism," attorney David Boies told NBC News. "What we know is that this was a state-sponsored attack on the privacy of an American corporation and its employees."

Boies praised the president's recognition of the gravity of the issue, and he said he hopes "all Americans can unite against what is really a threat to our national security."

"If state sponsored criminal acts like this can be directed against Sony, they can be directed against anybody," he warned.