Unicef Goodwill Ambassador Novak Djokovic visited a Unicef-supported child-friendly space in Belgrade to meet some of the refugee and migrant children who are passing through Serbia on their way to Western Europe.

Djokovic spent some time with the refugee children on 22 September and said that what they have had to endure deeply upsets him. "Seeing children that don't know if they will have the roof above their head, if they will have food on their table or water to drink. They don't know where they are going, where they are heading and what tomorrow brings. It's hurting me very much personally," Djokovic said during his visit.

He went on to call for everyone to do what they can to help deal with ongoing crisis. "I am asking everybody to show their good heart, their good will. I'm sure that if all of us adults feel responsibility and actually try to do something about it – all these children will have a home and their fundamental rights protected," said Djokovic.

Since the beginning of the year, 129,947 people have been registered in Serbia as asylum applicants. According to estimates from the United Nations refugee agency, UNHCR, at least the same number has passed through Serbia without registering. Unicef says almost 1,100 children, most aged between six and 10 years old, have so far rested and played in these safe Unicef-supported child-friendly spaces.

In response to the current crisis, Unicef Serbia has hired additional social workers in Presevo and Belgrade who are helping to identify the most vulnerable children and families and give them appropriate support. They are also helping to develop standard procedures for what to do when an unaccompanied child is identified.

EU leaders pledged at least €1bn (£720m, $1.1bn) for Syrian refugees in the Middle East and closer cooperation to stem migrant flows into Europe at a summit described as less tense than feared after weeks of feuding.