Sean Penn Wants Everyone to Remember There's a War in Ukraine, and 'It's Hell' (Exclusive)

Sean Penn has a new mission: to remind people that Ukraine remains in a horrific war against Russia, which he thinks many Americans have forgotten about.

"Look, it's almost two years in," Penn tells PEOPLE of the war in Ukraine. "And it's f------ hell."

Penn is releasing a new documentary called Superpower (streaming on Paramount+ beginning Monday night) which highlights the Ukrainian efforts to cling to their independence in the face of Russia's invasion.

The documentary began as a story about Ukrainian President Volodymyr Zelenskyy and his unlikely rise from comedic actor to president, but took a turn several days after filming began, when the war broke out. Now Penn hopes the footage and access he got inside Ukraine will help make a difference, or at the very least, open the eyes and hearts of the American people and its politicians.

"I think that because I was able to go there, we now have some real context to see how [this war] affects us and the rest of the world," Penn says. "And that we will end up involved in that one way or another if we don't take the opportunity that they've given us, which is to just support their freedom, and their self-defense, and their territorial integrity."

Penn has of course been involved in other times of crisis around the world, including rescuing people with his own boat after Hurricane Katrina, and bringing aid and relief to Haiti after the 2010 earthquake.

"I've had people report on previous activities of mine in their own way, without any information," he says of his past. "And they don't know me. They make their assumptions of 'Why this actor is going around doing whatever.' And I thought, 'You know, this time I'll just say, Hey, jump in the backpack, go with me and see what it really is.' And that's the effort of this film — to give people context for the reports they do read and hear about."

Penn says during the course of filming, he fell in love with the country and its people. "It's a beautiful place," he says. "We have to remember, three days before the war, they were like you and I. They were at the movie theaters, seeing the same movies we were."

Penn notes that he was particularly impressed by Zelenskyy, who gave Penn and his crew unique access during Ukraine's time of crisis.

"He's a quick study on the political dynamics around the world," Penn says of Zelenskyy, who had previously been an actor on a TV show that was, coincidentally, about an actor who becomes a president. "He also has a real command. He impresses very impressive people. I don't have those skills."

Penn adds, "The guy who really understands the global economy and how this war is effecting that. He's very good at communicating, and he's is been very level in really challenging times."

Penn hopes Superpower will not only inform viewers, but help make an impact.

"I think that I'm discovering more and more what my value can be in this way," he says of making films. "I don't know the answers, but I have impressions that I can share, not so much by talking about them, but by showing people what I see and letting them form their own impressions."

He adds, "I can be a tour guide, and I think I'm trusted because I'm trustworthy with the people that are in these critical positions."

Though Penn says he has no inclination to get into politics himself ("I'd rather die screaming of rectal cancer," he says), he does hope Superpower will also resonate with America's politicians — and that they get much more involved in the efforts to aid Ukraine in fighting back against the invasion.

"I know we will really be proud of ourselves if we get in on this thing, and we'll be on the right side of history," he says. "And we will totally recover all we've lost in reputation with our friends and their lives."