The United States has imposed new sanctions on North Korea as part of its first response to the cyber attack on Sony Pictures.
The FBI has blamed North Korea for the attack which leaked confidential data from Sony computers.
North Korea has denied the allegation but expressed fury over Sony's comedy The Interview, which features a plot to assassinate leader Kim Jong Un.
The FBI has released a warning to other businesses and theatres associated with as-yet unreleased comedy film The Interview could be targeted in cyber attacks.
A private document reportedly states that "anyone associated with the production, distribution and promotion" of the film "could possibly become the target of cyber attacks."
North Korea's dispute with the US over computer hacking took a new twist when the communist state lost Internet access for several hours.
A hacker group who claimed to be behind a cyber attack on Sony Pictures have posted a message online apparently mocking the FBI.
Events company Secret Cinema is planning to screen a film in protest at what they have called the 'censorship' of The Interview.