North Korea has accused the US of launching a series of hacking attacks against its networks in the latest developing in the escalating cyber cold war.
The nation's news agency reported the attacks on Friday according to number of sources.
"Intensive and persistent virus attacks are being made every day on internet servers operated by the North Korea," it said.
"It is nobody's secret that the US and the South Korean puppet regime are massively bolstering up cyber forces in a bid to intensify the subversive activities and sabotages against North Korea."
Commenting on the reports Jarno Limnéll, a doctor in military science and a director of cyber-security at security firm Stonesoft, said it would make sense for the US to target rogue nations like North Korea.
"It's an increasingly tense situation, and from a regional security point of view it's important for America to be seen to be flexing its muscles. In cyber warfare, offense is typically a step or two ahead of defence," he said.
"There is no such thing as a cast iron defence strategy when new threats and exploits emerge continually. As such, it is essential that sometimes the US candidly communicates the power of its offensive capabilities as a deterrent."
He likened the move to the "mutually assured destruction" scenario played out by Russia and the US in the Cold War.
"The threat of vastly destructive retaliatory cyber capabilities is a powerful deterrent for prospective enemies and rogue states," he added.
North Korea's claims come amid rising tensions among several nations over hacking attacks, with China and the US both accusing one another of attacks, although both sides have also sought to make peace over the issue.
This has also led to president Obama meeting with top business officials to discuss the threats, in the same week that the nation's director of national security placed cyber attacks the top threat facing the US.
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