Vladimir Putin's character was cut from the film before an actor was cast for the role. Putin, who was just three months into the job as Russian president when the tragedy occurred in 2000, was slated to appear as a supporting character in at least five scenes in the film. According to The Hollywood Reporter, EuropaCorp's president, Luc Besson, wanted to shift the story's focus to the rescue mission rather than the politics behind the disaster. One theory is that nobody at EuropaCorp wanted to be hacked. "Remember The Interview (2014)?" a source said, referring to the Evan Goldberg and Seth Rogen-directed comedy that angered Kim Jong-un and is believed to have sparked the infamous Sony hack in 2014. Ironically, the Russian leader is sympathetically portrayed in the original Kursk script, which highlighted why he took the tragedy personally (Putin's father was a submariner).
This is one of Michael Nyqvist's final films. He died of lung cancer in June 2017, a month before shooting was finished. However, according to The Guardian, Nyqvist completed his scenes.
The film shows Admiral Petrenko (Max von Sydow) as heading the public information panel: in reality it was actually headed by the Russian president, Vladimir Putin.
Thomas Vinterberg had the idea to make the character of Tanya a pregnant woman when he met Léa Seydoux, whose pregnancy was coming to an end.
The film was scheduled to start shooting in September 2016, but had to be postponed due to Russia's defense ministry not issuing a permit for the shoot, which would run for about a month. According to The Hollywood Reporter, the ministry originally promised cooperation with the production, but reportedly grew concerned about granting access to classified information and locations. The shoot was then relocated to France and Belgium and commenced at the Naval base of Toulon, France on April 26, 2017.