North Korean officials proposed a joint investigation with the United States into the cyber attack against Sony on Saturday and promised “serious” consequences if the offer is rejected, according to the Hollywood Reporter.

An unidentified spokesman for the country said in a statement carried by Pyongyang’s official Korean Central News Agency:

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 North Korea.

We have a way to prove that we have nothing to do with the case without resorting to torture, as the CIA does.

American analysts reportedly believe North Korean officials know that U.S. would never accept the offer for a joint investigation and are simply deploying a political tactic.

U.S. officials have blamed North Korea for the hacking, citing the tools used in the attack against Sony Pictures Entertainment.

The hacking resulted in the disclosure of tens of thousands of confidential Sony documents, and escalated to threats of terror attacks against American movie theaters. Those threats caused Sony to cancel the Christmas Day release of The Interview, after national theaters announced they would opt-out of showing the film.

A professor at Seoul’s Dongguk University called the North’s proposal “typical” in reference to previous disputes North Korea has had with rival countries. “They are now talking about a joint investigation because they think there is no conclusive evidence,” Koh Yu-hwan said. “But the U.S. won’t accede to a joint investigation for the crime.”