The North Korea's powerful National Defence Commission (NDC) also accused the US of "disturbing the Internet operation" of North Korean media outlets.
The country suffered Internet blackouts this week, triggering speculation that US authorities may have launched a cyber-attack in retaliation for the hacking of Sony Pictures -- the studio behind madcap North Korea comedy "The Interview" -- which Washington says was carried out by Pyongyang.
The NDC accused Obama of taking the lead in encouraging theatres to screen "The Interview" on Christmas Day. Sony had initially cancelled its release after major US theatre chains said they would not show it, following threats to movie-goers by hackers.
"Obama always goes reckless in words and deeds like a monkey in a tropical forest," a spokesman for the NDC's policy department said in a statement published by the North's official KCNA news agency.
"If the US persists in American-style arrogant, high-handed and gangster-like arbitrary practices despite (North Korea's) repeated warnings, the US should bear in mind that its failed political affairs will face inescapable deadly blows," the NDC spokesman said.
He accused Washington of linking the hacking of Sony to North Korea "without clear evidence" and repeated Pyongyang's condemnation of the film, describing it as "a movie for agitating terrorism produced with high-ranking politicians of the US administration involved".
The movie took in a million dollars in its limited-release opening day, showing in around 300, mostly small independent theatres. It was also released online for rental or purchase, AFP reported.