The UN’s top official on refugees on Wednesday urged Greece to improve conditions in refugee camps, saying Europe must do more for the country.

Speaking to reporters after visiting refugee camps on Greece’s Aegean island of Lesbos, UN High Commissioner for Refugees Filippo Grandi told reporters that the deplorable conditions at the camps need to be improved.

“These living conditions need urgent improvement,” Grandi said.

Grandi said he will meet Greek government officials to discuss addressing conditions at the camps.

He said he is “very worried” about the condition of unaccompanied refugee children.

Read more: UN urges Greece to improve conditions in refugee camps