Sitting in a bare, apparently windowless room, Zelenskiy speculated on Vladimir Putin’s motives for the invasion.

“He wants us to be dead,” Zelenskiy said of the Russian president in the central scene in “Superpower”, a film-length profile of the Ukrainian leader that premiered on Friday at the Berlin Film Festival. “He hates Ukraine. He hates us.”

Directed by Penn and Aaron Kaufman, the movie opens in the months before the invasion, with Penn intrigued by a fellow actor’s transition from the film set to presidential office. The invasion dramatically raises the stakes, turning Penn into a passionate advocate for Ukraine’s cause.

In fighting against the Russian invasion, Ukraine is “fighting a fight on all of our behalf”, Penn told the audience at the premiere.

Produced by Vice and shot in the close-in, handheld, web documentary style popularised by the media organisation, the film charts a chain-smoking, vodka-tonic-sinking Penn’s efforts to understand Ukraine, its president, and its fight.

Penn and Kaufman advocate in the film for the United States to arm Ukraine, and in doing so make it clear that Zelenskiy’s decision to receive them on the first day was a deft move in Ukraine’s information war.

“If we don’t win today, then Americans will be fighting wars in some years’ time,” Zelenskiy tells Penn in a later interview, warning that a Ukrainian loss would have consequences further afield.

Nearly one year into the invasion, Putin’s troops are still in Ukraine, intensifying assaults in the east in what Moscow calls a “special military operation” that has killed thousands and led millions to flee.

The camera brings the viewer uncomfortably close to the death and gore left by retreating Russian soldiers, and is honest about the limits of what a Hollywood film star will go through.

“Can I be blunt?” one minder is heard saying. “You’re Sean Penn. Nobody is going to be responsible for you dying on the front line.”