BERLIN - American actor-director Sean Penn premiered Superpower, his admiring portrait of Ukrainian President Volodymyr Zelensky at war, telling the Berlin film festival on Saturday that the movie was also a wake-up call about Americans’ own fragile democracy.

The two-time Oscar winner was in Kyiv making a documentary about Mr Zelensky’s rise from comedian to national leader when Russia invaded Ukraine nearly one year ago.

In a series of interviews on that first terrifying night and during the initial months of the onslaught, Penn and Mr Zelensky built up what they both call a close friendship.

“It was a very moving way to start to get to know somebody,” Penn told reporters.

“Aside from meeting my children at their birth, the highlight of (my life was) meeting and sensing a great human heart of courage that day with that man.”

Mr Zelensky joined Penn by video link at the festival’s opening ceremony on Thursday to ask for the entertainment industry’s sustained help in keeping Western countries united behind Ukraine.

“Cinema cannot change the world,” said Mr Zelensky. “But it can influence and inspire people who can change the world.”

The actor stresses in the film that the more quickly the war is ended, the less likely “Americans will have to fight” one day in a Russian war against Nato.

Penn, who appears in almost every scene of the two-hour movie made for Vice Media, said he was okay with being called a “propagandist”.

“We made a very unapologetically biased film because that was the true story we found,” he said.

Often self-deprecating on screen, the actor admits he was a naive “Pollyanna” before the war, never believing that Russia’s President Vladimir Putin would go through with a full-scale invasion.

As he heads to the front line in the Donbas region, he jokes when he is handed a knife that the Ukrainian people can now rest easy because “Sean Penn is armed”, before brandishing two clenched fists at the camera.

In addition to Mr Zelensky, Penn speaks with diplomats, reporters and analysts as well as Ukrainian soldiers and pro-democracy activists to offer an “idiot’s guide” to the last decade of Ukrainian history.

The film’s title comes from a scene in Mr Zelensky’s hit comedy show, Servant of the People, in which he tells his young son that he will protect him from any threat using his “superpower” – his love for his family.

But it is also an ironic reference to the United States and Russia. Penn argues that Ukraine could be now seen as “the better us” – a new global beacon for freedom and democracy.

“Growing up in the United States – this won’t be news to you – we are born with a misguided sense of exceptionalism,” Penn said.

He noted that while America was now riven with political and cultural strife, he found in Ukraine “absolute unity pursuing all those things that without which life is not worth living”.

“These people are doing what they have to do simply because they love their country and they love each other,” he said.

“So the lesson is simple and we should all honour them by doing our best to follow it.”

He called for the West to step up its military support for Ukraine.

“The most significant humanitarian response that can happen right now is the delivery and supply of long-range precision missiles,” he said.

Initial reviews of the film were mixed, with The Hollywood Reporter calling the project “both vital and vain”.

“It would be easy to write the whole thing off as one big and slightly dangerous vanity project, but let’s be honest: This war concerns all of us, and the actor is doing all he can to help the good guys,” its reviewer Jordan Mintzer wrote.

Superpower is running out of competition at the Berlin film festival, Europe’s first major cinema showcase of the year. The 11-day event is spotlighting Ukraine with a series of new documentaries and feature films. AFP