The United States hit North Korea with new sanctions this month
after the FBI said the country was behind the attack. Some technology experts say others could be involved, such as former employees of the studio. But the FBI director has expressed
"not just high confidence, but very high confidence," that North Korea was behind the hacking.
In a rare press briefing on Tuesday, An Myong Hun, North Korea's deputy U.N. ambassador, emphatically denied his country's involvement.
"My country has nothing to do with the Sony hacking. It is out of sense to do that, and we very want United States to provide evidence," An said.
He said that North Korea had offered last week to the United States to "undertake joint investigation" into the hacking scandal.
Despite having applauded the hacking "a righteous deed" and condemning "The Interview" as "a disgusting movie openly agitating terrorism against a sovereign state," North Korea has consistently denied responsibility. At the same time, it has blamed the U.S. government for being behind the making of the Seth Rogen-James Franco film. North Korea government has warned the United States that its "citadels" will be attacked, dwarfing the hacking attack on Sony.
At a briefing on the subject, Rep. Ed Royce, a California Republican and chairman of the House Foreign Relations Committee, called to "cut off hard currency" so North Korea cannot carry out offensive attacks like the cyber attacks.
U.S. hits back with sanctions
The attack on Sony Pictures used "a sophisticated worm to conduct cyber exploitation activities," said retired Brigadier Gen. Gregory J. Touhill, who serves as deputy assistant secretary for cybersecurity operations and programs at the Department of Homeland Security. Sony Pictures made "The Interview," a comedy depicting the assassination of North Korean leader Kim Jong Un.
The White House imposed sanctions this month targeting leaders in North Korea's government, preventing them from accessing property and entering the United States. The isolated nuclear regime, which has denied involvement in the Sony hack, was already subject to a strict set of U.S. economic restrictions.
"We have made clear that we will respond to the DPRK's misbehavior," said Sung Kim, the U.S. special representative for North Korea policy. "We are under no illusions about the DPRK's willingness to abandon its illicit weapons, provocations and human rights abuses on its own."
The U.S. Department of Treasury has designated three North Korean entities -- including the Reconnaissance General Bureau, the Korea Mining Development Trading Corporation and Korean Tangun Trading Corporation -- and 10 officials based around the world as "critical North Korean operatives." The aim of the sanctions is to isolate North Korea and cut off their entities from being able to use the international financial system, said Daniel Glaser, assistant secretary of the Department of Treasury, during a briefing about the hacking on Tuesday.
Royce, the committee chairman, urged for stronger measures against North Korea.
"We need to step up and target those financial institutions in Asia and beyond that are supporting the brutal and dangerous North Korean regime," he said. "Such sanctions have crippled North Korea in the past, leaving the regime unable to buy the loyalty of its generals."