Angelina Jolie on Monday said it's critical that neighboring countries continue to welcome all those fleeting Ukraine after Russian invasion of the country.
The actress, who is a UN special envoy for refugees, said "More than half a million people have fled Ukraine to neighboring countries in the past several days."
Jolie said UNHCR estimates it may be up to 4 million if the situation escalates further.
Russian forces have killed hundreds of people and destroyed infrastructure since they invaded Ukraine last week.