Sean Penn voices support for Ukraine amid Russian invasion

Sean Penn voiced support for Ukraine amid the ongoing Russian attacks.

After spending months documenting the war, the actor, 61, told Hollywood Authentic magazine that he recently thought about fighting on behalf of Ukraine.

"If you've been in Ukraine [fighting] has to cross your mind," he said in the interview published Saturday. "And you kind of think what century is this? Because I was at the gas station in Brentwood the other day and I'm now thinking about taking up arms against Russia? What the f--- is going on?"

Amid the start of the Russian invasion in late February, Penn traveled to Ukraine to work on an upcoming documentary about political tensions, chronicling the invasion and war launched by Russian President Vladimir Putin.

"The only possible reason for me staying in Ukraine longer last time would've been for me to be holding a rifle, probably without body armour, because as a foreigner, you would want to give that body armour to one of the civilian fighters who doesn't have it or to a fighter with more skills than I have, or to a younger man or woman who could fight for longer or whatever," he told Hollywood Authentic.

In a statement shared with PEOPLE in February, Penn expressed his thoughts on the horrors that the Ukrainian people are facing.

"[It is] already a brutal mistake of lives taken and hearts broken, and if he doesn't relent, I believe [Russian president] Mr. [Vladimir] Putin will have made a most horrible mistake for all of humankind," he said.