“I don’t think it was an act of war,” Obama said in an interview on CNN’s “State of the Union” program that aired today. “It was an act of cyber vandalism that was very costly, very expensive. We take it very seriously. We will respond proportionately.”

The president’s characterization of the attack as cyber vandalism drew a swift rebuke from Senator John McCain of Arizona, the incoming Republican chairman of the Senate Armed Services Committee.

“It’s more than vandalism,” McCain said on the same CNN program. “It’s a new form of warfare that we’re involved in and we need to react, and react vigorously.”

Obama also said the U.S. is reviewing whether to put North Korea back onto its list of state sponsors of terrorism. He told CNN that the U.S. will examine the facts to determine whether North Korea belongs on the list from which it was removed in 2008.

Clear Criteria

“We’ve got very clear criteria as to what it means for a state to sponsor terrorism,” Obama said. “And we don’t make those judgments just based on the news of the day.”

Sony canceled the Dec. 25 release of “The Interview,” a comedy film about a fictional plot to assassinate North Korean leader Kim Jong Un, after computer hackers threatened violence against theaters that show the film. Those hackers, who called themselves the Guardians of Peace, had previously released private e-mails from Sony.

Obama said at a news conference Friday that Sony “made a mistake” in deciding to cancel the film’s release. Sony Pictures Chief Executive Officer Michael Lynton told CNN in a separate interview that he did “reach out and speak to senior folks at the White House” and “informed them that we needed help.”

In the CNN interview taped Friday after his news conference, Obama suggested he wasn’t involved in any discussions that took place before Sony’s decision was made.

Cybersecurity Law

“Had they talked to me directly about this decision, I might have called the movie theater chains and distributors and asked them what that story was,” he said.

The president called on Congress to pass a cybersecurity law and for the government to help companies “harden their sites” to prevent hacking.

“In the meantime, when there’s a breach, we have to go after the wrongdoer,” Obama said. “We can’t start changing how we operate.”

Obama didn’t specify what steps he’s prepared to take against North Korea.

Senator Lindsey Graham, a South Carolina Republican on the Armed Services Committee, said Obama should increase sanctions, put North Korea back on the list of state sponsors of terrorism, and “put China on notice” that it needs to help rein in Kim’s regime.

Graham, like McCain, faulted Obama for equating the attack on Sony to vandalism. “It’s an act of terrorism,” Graham said.

The North Korean government said it had nothing to do with hacking, which paralyzed Sony’s computer systems and stole sensitive e-mails and documents.

‘Groundless Allegations’

“As the U.S. is spreading groundless allegations and slandering us, we propose a joint investigation,” the country’s foreign ministry said in an e-mailed statement cited by the state-run Korea Central News Agency. It warned of “grave consequences” if the U.S. fails to take up its offer.

Malicious software in the Sony attack bore links to malware previously used by North Koreans, according to the Federal Bureau of Investigation. The hacking tools used were also similar to those used in a March 2013 attack on South Korean banks and media organizations, it said.

The U.S. is now seeking help from China, North Korea’s largest trade partner, in investigating the attack on Sony, according to administration officials familiar with the case.

“That’s the problem,” said Fran Townsend, a former homeland security adviser to President George W. Bush who spoke on ABC’s “This Week” program today. “It’s not clear that the Chinese will help us here.”

In his final interview before heading to Hawaii for a Christmas vacation, Obama also defended his decision to restore relations with Cuba, denied that he has been outmaneuvered by Russia and Iran, and vowed to “do everything I can” to close the Guantanamo Bay prison camp.

Something New

“Cuba offers us an example of an opportunity to try something different,” said Obama, who last week announced plans to ease travel and trade rules and restore diplomatic relations. “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.”

He also said he will review whether Cuba should remain on the U.S. list of countries that sponsor terrorism. When asked if it would be hard to have relations with Cuba while it remains on the list, Obama said, “I think so.”

While pledging to pursue his efforts to close Guantanamo, which now holds 132 suspected terrorists, Obama acknowledged there are still prisoners there who can’t be tried in federal courts because of a lack of evidence, and shouldn’t be released because they’re still considered dangerous.

“We’re going to have to wrestle with that,” he said.

–With assistance from Angela Greiling Keane, Chris Strohm and Richard Rubin in Washington.