MOSCOW -- Russia on Thursday offered sympathy to North Korea amid the Sony hacking scandal, saying the movie that sparked the dispute was so scandalous that Pyongyang's anger was "quite understandable."

Washington failed to offer any proof to back its claims of Pyongyang's involvement in the hacking, Russian Foreign Ministry spokesman Alexander Lukashevich said at a briefing, adding that the U.S. threats of retaliation were "counterproductive."

The U.S. has blamed Pyongyang for the recent cyberattack on Sony Pictures, which produced "The Interview," a comedy depicting the assassination of North Korean leader Kim Jong Un. Pyongyang has denied a role in the hacking, but also praised it as a "righteous deed."

Sony initially decided not to release the film because of threats against U.S. cinemas, but released the movie online Wednesday.

Russia's ties with the communist North soured after the 1991 Soviet collapse, but have improved under President Vladimir Putin's watch. Moscow has taken part in international efforts to help mediate the standoff over Pyongyang's nuclear and missile programs, although its diplomatic efforts have had little visible effect.

Last week, the Kremlin said that it had invited Kim to Moscow in May to attend festivities marking the 70th anniversary of the victory over Nazi Germany.

Commenting on the Sony hack scandal, Lukashevich said that "the concept of the movie is so aggressive and scandalous, that the reaction of the North Korean side, and not just it, is quite understandable."

He went on to say that Pyongyang had offered to conduct a joint investigation into the incident, adding that the proposal could help ease tensions and reflected a "sincere desire of the North Korean side to study the issue in detail."

"We perceive the U.S. threats to take revenge and calls on other nations to condemn the Democratic People's Republic of Korea as absolutely counterproductive and dangerous, as they only would add tensions to the already difficult situation on the Korean Peninsula and could lead to further escalation of conflict," Lukashevich said.