North Korea Is Experiencing a Full Internet Blackout

North Korea's Internet services went completely offline Monday, according to a network-monitoring company, a blackout that comes just days after U.S. authorities formally blamed the secretive, authoritarian regime for the recent Sony Picture hack.

The reclusive state began experiencing Internet challenges on Sunday and went completely off the grid Monday, according to New Hampshire-based Dyn Research.

After 24hrs of increasing instability, North Korean national Internet has been down hard for more than 2hrs pic.twitter.com/hDbitXBoqp

— Dyn Research (@DynResearch) December 22, 2014

It remains unclear what is causing the outage, though the timing is likely to prompt speculation that it is a retaliatory move waged by U.S. authorities. A White House spokesman declined to comment on the apparent blackout, saying "we don't have anything additional on North Korea to share today."

"While we cannot confirm the source of the North Korean internet outage, we can confirm that a large number of connections have been withdrawn and that North Korea does not currently have access to the web," a spokeswoman for the Internet company Cloudflare said in a statement.

Just hours after the FBI announced on Friday it had definitively concluded North Korea was behind the devastating cyberattack on Sony, President Obama promised to "respond proportionally and in a manner that we choose," though he elided specifics about what that might entail.

Reports surfaced over the weekend suggesting that the Obama administration was asking China for help to thwart North Korea from launching any future attacks, which it had threatened—while maintaining its innocence—after being blamed for the Sony hack.

Nearly all of North Korea's telecommunications services run through Chinese networks.

Obama told CNN's Candy Crowley that North Korea's Sony attack amounted to an "act of cybervandalism," but he added that he did not believe it constituted an "act of war."

The breach of Sony's computer networks, which began nearly a month ago, has cost the movie studio hundreds of millions. It culminated in the canceled Christmas Day release of the comedy film The Interview after the hackers, calling themselves "Guardians of the Peace," threatened 9/11-scale violence against moviegoers of the film's premiere went forward.

Sony is currently mulling alternative ways to release The Interview, a comedy that portrays Seth Rogen and James Franco as dimwitted celebrities who travel to the hermetic country on a secret CIA-backed mission to assassinate its oppressive dictator, Kim Jong-Un.

Brendan Sasso contributed to this article.