North Korea has threatened to target the White House and the US mainland in the row over the cyber attack against Sony.

The hack led to the comedy The Interview, about a plot to assassinate Kim Jong Un, being shelved.

US President Barack Obama has described the hacking as an act of "vandalism", and is considering putting North Korea back on its terror list.

"I don't think it was an act of war. I think it was an act of cyber vandalism that was very costly, very expensive," Mr Obama said in a TV interview.

"We take it very seriously. We will respond proportionately."

North Korea spent two decades on the list until the Bush administration removed it in 2008 during nuclear negotiations. Some politicians in the US have called for the designation to be restored following the hack.

The US believes that Pyongyang is behind the hack attack, which also involved the embarrassing leak of scores of private emails of Hollywood stars and industry executives.

North Korea insists it had nothing to do with the cyber-attack on Sony and has proposed a joint investigation with the US.

The LA Times national correspondent, Robin Abcarian, told Newstalk Breakfast that the scandal has provoked outrage among the US public.