Cinema attacks threatened ... billboard for ‘The Interview’ in Hollywood, Los Angeles, posted before the film’s release was cancelled. Picture: AP Photo/Damian Dovarganes Source: AP

The country’s top military body, the National Defence Commission (NDC), again denied involvement in the hacking of Sony Pictures, which prompted executives to halt the release of a film seen by Pyongyang as mocking the North’s leader.

US President Barack Obama said on Friday it was confirmed that the North carried out the hacking.

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Movie giant ... US President Barack Obama says Sony ‘made a mistake’ in shelving the satirical film ‘The Interview,’ about a plot to assassinate North Korea's leader. Picture: AP Photo/Damian Dovarganes Source: AP

“We will respond proportionately and we’ll respond in a place and time and manner that we choose,” he said.

The North’s NDC, in a statement on the official news agency, said its army and people “are fully ready to stand in confrontation with the US in all war spaces including cyber warfare space to blow up those citadels”.

“Our toughest counteraction will be boldly taken against the White House, the Pentagon and the whole US mainland, the cesspool of terrorism, by far surpassing the ‘symmetric counteraction’ declared by Obama,” it said.

The North, which has in the past made statements threatening the US mainland, accused the Obama administration of being “deeply involved” in the making of the comedy movie The Interview, which concerns a fictional CIA plot to kill Pyongyang’s leader Kim Jong-Un.

Change of plans ... a billboard for the ‘The Interview’ on display in Venice, California. Picture: Christopher Polk/Getty Images Source: Getty Images

It again praised the “righteous action” by the hacking group, which has styled itself Guardians of Peace, but said it was unaware where they were based.

The FBI has cited “significant overlap” between the attack and other “malicious cyber-activity” with direct links to Pyongyang, including an attack on South Korean banks blamed on the North. The North said in Sunday’s statement it has never attempted or made a cyber-attack on South Korea.

“It is common sense that the method of cyber warfare is almost similar worldwide,” it added.

The United States is mulling whether or not to place North Korea back onto its list of state sponsors of terrorism, US President Barack Obama said in an interview aired on Sunday.

Under review ... the United States is mulling whether or not to place North Korea back onto its list of state sponsors of terrorism, US President Barack Obama said. Picture: AFP/Brendan Smialowski Source: AFP

“We’re going to review those through a process that’s already in place,” the US president said in an pre-taped interview on CNN. “And we don’t make those judgments just based on the news of the day. We look systematically at what’s been done and based on those facts, we’ll make those determinations in the future.”

Mr Obama’s remarks, in the interview which taped on Friday, followed a call from a leading US senator to re-consider North Korea’s terror designation.

Senate Foreign Relations Committee Robert Menendez wrote to Secretary of State John Kerry on Friday, saying the Pyongyang regime had set a “dangerous precedent” through cyber attacks that were “able to inflict significant economic damage on a major international company.” The State Department rescinded its designation of North Korea as a state sponsor of terrorism in October 2008.

Currently, the list includes just four countries: Cuba, Iran, Sudan and Syria.

‘Toughest counteration’ ... North Korea has threatened to hit back at the White House and other US targets if Washington sanctions it for an alleged hacking attack. Picture: Elisabeth Mealey Source: Supplied

Obama has asked the State Department to consider removing Cuba, following the historic thawing of relations between the two Cold War rivals announced earlier this week.

Meanwhile, the United States has asked China to help block cyber attacks from North Korea as it weighs a response to the crippling hack of Sony Pictures.

“We have discussed this issue with the Chinese to share information, express our concerns about this attack and to ask for their co-operation,” a senior US administration official told AFP.

Controversial ... Diana Bang, Seth Rogen and James Franco in ‘The Interview’. Picture: AP Photo/Columbia Pictures/Sony/Ed Araquel Source: AP

China is North Korea’s closet ally, and has traditionally had longstanding influence with the leaders of the hermit state. The US administration official said that in “our cybersecurity discussions, both China and the United States have expressed the view that conducting destructive attacks in cyberspace is outside the norms of appropriate cyber behaviour.”

The US and China last year set up a special panel to discuss cybersecurity.

But earlier this year, in an unprecedented move Washington charged five members of a shadowy Chinese military unit with hacking US companies to winkle out their trade secrets.

In the first-ever prosecution of state actors over cyberespionage, a federal US grand jury indicted the five on charges of breaking into US computers to benefit Chinese state-owned companies, leading to job losses in the United States in steel, solar and other industries. The five remain at large however.

It is unclear how the United States will choose to retaliate against North Korea.

Addressing reporters after the FBI said Pyongyang was to blame, Mr Obama said Washington would never bow to “some dictator”.

Washington won’t bow to ‘dictator’ Kim Jong-un ... US President Barack Obama indicates there will be a ‘proportionate’ response to the Sony cyber attack. Picture: AP/Wong Maye-E Source: AP

While Mr Obama said he was sympathetic to Sony’s plight, he also said the movie giant had “made a mistake” in cancelling the release.

Sony defended its decision, made after anonymous hackers invoked the 9/11 attacks in threatening cinemas screening the film, which prompted theatre chains to say they would not risk showing it. North Korea said insults against “our highest authority” would not be tolerated, but it rebuffed the notion of cinema attacks. “But in case we have to retaliate, we would not carry out terrorist attacks on innocent viewers at movie theatres but stage frontal attacks on those who are responsible for the hostile activities against the DPRK (North Korea) and their headquarters,” the spokesman said.