"No access for more than a week. People use snow and rainwater, they hack into heating systems to get access to water there, but many people have already run out of water, as well as food. I think we can say we're in a crash phase right now," - Wade added.
"Doctors Without Borders" reports that people are dying due to a lack of access to medicines.
"In the next phase, we will see people who could potentially die from dehydration and starvation or… those who flee the city in search of food and water and die from violence outside the city," - he said.
Earlier, Deputy Prime Minister and Minister for Reintegration of the Temporarily Occupied Territories of Ukraine Iryna Vereshchuk said that the occupiers were blocking the approaches to Mariupol for Ukrainian humanitarian convoys.