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.
North Korea said fresh US sanctions issued by President Barack Obama are 'hostile and repressive' policies by Washington.
President Obama issued an executive order authorising expanded sanctions against North Korea in the wake of the hacking of Sony Pictures Entertainment, which Washington blamed on Pyongyang.
In a statement from North Korea's foreign ministry on the state-run KCNA news agency the Communist country said: "The policy persistently pursued by the US to stifle North Korea, groundlessly stirring up bad blood towards it, would only harden its will and resolution to defend the sovereignty of the country."
It added: "The persistent and unilateral action taken by the White House to slap 'sanctions' against North Korea patently proves that it is still not away from inveterate repugnancy and hostility toward the country."
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.