‘We will respond’: Obama vows retaliation after Sony hacks traced to North Korea

The US has vowed to respond to North Korea's hacking attacks on Sony, as the entertainment company's CEO speaks out following the removal of controversial comedy The Interview from cinemas.

The film, starring Seth Rogen and James Franco, depicts a fictional assassination attempt on North Korean dictator Kim Jong-un.

Hackers, whom the FBI have traced to the rogue state, damaged Sony's image by releasing a number of embarrassing emails between high-level Hollywood identities and company figures.

Cinemas preparing to show the film were also threatened.

The removal of The Interview has been widely derided as cowardly, but Sony CEO Michael Lynton defended the decision.

"At that time, we had no alternative," he said.

President Barack Obama has also promised to address the issue.

"(The hackers) caused a lot of damage and we will respond," he said.

"We cannot have a society in which some dictator someplace is imposing censorship on the United States."

Senior Republicans, including former presidential candidate John McCain, compared the cyber-attacks to an act of war.