In an interview with the American broadcaster CNN, President Obama said his administration was examining the facts to determine whether North Korea should be classified as a state that sponsors terrorism.
"We are going to review those (facts) through a process that is already in place," the president told CNN's "State of the Union" show, which was recorded on Friday and will be aired later today.
"And we don't make those judgments just based on the news of the day. We look systematically at what has been done and based on those facts, we'll make those determinations in the future."
The East Asian communist state was on the US terror list for two decades until 2008, when former President George W. Bush removed it to facilitate nuclear talks. Iran, Sudan, Syria and Cuba are now the only countries that remain on the list.
'An act of cyber-vandalism'
The White House said on Saturday it stood by the conclusion of the Federal Bureau of Investigation (FBI) that Pyongyang was to blame for a hacking attack that led Sony Pictures´Entertainment to cancel its release of the movie "The Interview," a comedy about a plot to assassinate the country's leader, Kim Jong Un.
Obama described the cyber-attack as a "very costly, very expensive" act of cyber-vandalism. The US president, however, fell short of calling it an act of war.
"We take it very seriously. We will respond proportionately," he said.
North Korea called the US accusations "groundless slander," proposing a joint investigation with the US into the cyber-attack, which resulted in the disclosure of a huge quantity of internal Sony data, including unreleased films, personal information on employees and executive emails.
The FBI said on Friday that analysis of the malware and internet infrastructure used in the hacking attack showed a "significant overlap" with "other malicious cyber activity" previously linked with North Korea, but gave little more detail on how it reached its conclusion.
On Friday, Obama criticized Sony executives for giving in to the hackers' threats to attack cinemas screening the film, saying that the decision was tantamount to a form of censorship that set a dangerous precedent.
shs/tj (AP, AFP, Reuters)