Pyongyang is adamant, stating once again Saturday that it had nothing to do with the cyberattack on Sony, and that President Obama’s statements to the contrary amount to nothing more than “groundless slander.” In fact, North Korea is so convinced it had nothing to do with the hack that it wants to launch a joint investigation with the United States into the incident to figure out the real culprit, according to the Reuters translation of a story published by the state-run Korean Central News Agency. What’s more, a spokesman of North Korea’s Foreign Ministry warned of “serious consequences” if Washington refuses to cooperate in the probe, and if the U.S. continued to insist North Korea was responsible for the attack it only recently had called a “righteous deed” by its “supporters and sympathizers.”

“The U.S. should bear in mind that it will face serious consequences in case it rejects our proposal for joint investigation and presses for what it called countermeasures while finding fault with [Pyongyang],” the unnamed spokesman said. “We have a way to prove that we have nothing to do with the case without resorting to torture, as the CIA does.”

North Korea is a fan of proposing joint investigations it knows will be rejected in a bid to sound sincere, an analyst tells the Associated Press. In 2010, for example, Pyongyang said it wanted to carry out a joint investigation with South Korea, which blamed the North for a torpedo attack that killed 46 of its sailors. “They are now talking about a joint investigation because they think there is no conclusive evidence,” Koh Yu-hwan, a professor at Seoul’s Dongguk University, said. “But the U.S. won’t accede to a joint investigation for the crime.”