he United States did carry out limited cyber-operations against North Korea in response to the communist nation's alleged hacking attack on Sony Pictures, but the operations did not cause the North's Internet outage, a report said Tuesday.

North Korea's Internet connections suffered outages for days in late December after U.S. President Barack Obama blamed the communist nation for the massive hack on Sony and promised a "proportional response."

But the U.S. has since neither confirmed nor denied its role in the North's Internet outages.

The issue re-emerged last week as Rep. Michael McCaul (R-TX), chairman of the House Homeland Security Committee, told a cyber-security event in Washington that the North's Internet outage was retaliation for the Sony hack.

The lawmaker was quoted as saying, "There were some cyber responses to North Korea."

On Tuesday, the online news outlet Daily Beast cited unidentified sources with knowledge of the U.S. government cyber-operations against North as saying that the operations were "designed to send a message that North Korean officials weren't beyond the reach of the American government."

The U.S. operations took place before the blackout, but the takedown itself was not the result of those operations, the sources were quoted as saying. The report also said independent hackers have claimed they are the ones that took the North offline.

Former U.S. intelligence officials were also quoted as saying that the American government would hesitate to take down the North's entire network because it would cut intelligence agencies off from the cyber-spying they were doing inside North Korea.

It also cited a senior U.S. intelligence official recently saying that spying on the North's networks was mainly to gather information about its nuclear weapons program and to get insights into its thinking. The National Security Agency considers North Korea a priority target and has a unit dedicated to covering it, former officials said.

In an interview with Fox TV on Sunday, CIA Director John Brennan neither confirmed nor denied speculation that the U.S. was behind the North's Internet disruptions, only saying that the North's infrastructure is rickety and its Internet system has problems. (Yonhap)