The Mystic River actor is making a documentary about the Russia-Ukraine crisis for Vice Studios and flew into Ukraine's capital city, Kyiv, last week before Russia launched a full-scale attack on Thursday.

Sharing an update about his experience on the ground on Monday, the 61-year-old revealed he and his colleagues have fled the country like many other Ukrainians.

"Myself & two colleagues walked miles to the Polish border after abandoning our car on the side of the road." Penn wrote on Twitter.