North Korea has lashed out at US President Barack Obama, likening his actions to those of a "monkey" in the latest development over a hacking row that began when the Federal Bureau of Investigation accused Pyongyang of masterminding a cyberattack on Sony Pictures Entertainment.

The North's powerful National Defence Commission, the country's top governing body led by President Kim Jong-un, said that Obama was behind the release of "The Interview," a satirical comedy that Sony Pictures had cancelled after last month's cyberattack.

Pyongyang has described the movie, which casts Kim as a "buffoon", as illegal, dishonest and reactionary.

"Obama always goes reckless in words and deeds like a monkey in a tropical forest,'' an unidentified spokesman at the commission's Policy Department said in a statement carried by the official Korean Central News Agency.

North Korea, which blamed Obama for this week's shutting down of its internet, has proposed a joint investigation into the hacking and denied responsibility for the cyberattack.

Internet outage

Pyongyang suffered an unprecedented internet outage, with analysts saying the country's web access was cut entirely for a time. The outage happened after the US had promised to respond to the Sony hack.

The US government has declined to say if it was behind the shutdown.

"The US, a big country, started disturbing the Internet operation of major media of the DPRK, not knowing shame like children playing a tag," the defence commission said.

It was not the first time North Korea has used crude insults against Obama and other top US and South Korean officials. Earlier this year, the North called US Secretary of State John Kerry a wolf with a "hideous" lantern jaw and South Korean President Park Geun-hye a "prostitute".

In May, the North's news agency published a dispatch saying Obama has the "shape of a monkey".

There was no immediate reaction from the White House on Saturday.

Source: Al Jazeera and agencies