Los Angeles, Mar 7 (IANS): Oscar-winning actor Sean Penn recently returned to the US after spending time at the Ukrainian border, and shared his experience of the refugee crisis that's taking place in eastern Europe.

The 61-year-old star, who has been filming a documentary for Vice Films, told 'Anderson Cooper 360': "We had the luxury of being able to abandon a rented vehicle on the side of the road. This was a startling thing to me; it was mostly women and children, some in groups and some just a mother and her child, in almost all of those cars.

"In some cases, the father was dropping them off and returning, because we know that from 18 to 60, men are not to leave, they're to stay in the resistance against Russia."

More than a million people are believed to have fled Ukraine since the start of the Russian invasion, reports femalefirst.co.uk.

Penn was astonished by the scale of the refugee crisis.

He recalled: "I didn't see any luggage. It was as though they wanted to believe they're going to be able to come back, and there was an immediacy to leave because of the incredible amount of people leaving and how long it takes to get out of the country now.

"So, the car is pretty much, aside from those who have family or friends that could help on the other side, all they have.

"So, in the several miles that we walked after abandoning our car, I didn't see one of those cars move a car length because that line was so slow. And then you get there and you see all those who have walked as well in that crowd."

Despite this, Penn was glad that he got to witness the situation at first hand.

"I was glad, not so much in the moment, but I was glad to have had the experience of having to see what it was to get through that border ... what it is to just sit there for sometimes days."