Earlier this year Novak Djokovic was appointed a goodwill ambassador for Unicef.
It was as part of this role that the number one men's tennis player in the world met refugees at a centre in Belgrade, where they were given shelter and supplies before continuing their onward journey in the EU.
The Paris terror attacks have brought the refugee crisis back on to the political agenda, with renewed calls for Europe to close its borders.
Djokovic was asked about the situation in his native Serbia after beating Kei Nishikori at the ATP World Tour Finals at London's O2 Arena.
On the refugee crisis, he said:
You've got to get to the bottom of that, got to get to the cause. The cause is the war back in their country. And you can't blame these people, if they don't have a house, have nothing, where are they going to go? Of course, they have to search for some better place to live.
I think it's an obligation of all the countries to give them this right.
On his visit to the refugee shelter in the Serbian capital, he said he was deeply affected by seeing a child he was playing with be taken away by their mother so they could continue their journey to "they don't even know where".
The 28-year-old added:
I'm very proud as a Serbian seeing what my people have done for these migrants, people that have suffered so much. They offer them that shelter, home, food and drink, that's the most basic things in life.
From my perspective I'm only an athlete, obviously I'm following this as a human being. At the end of the day we all have to be humans and feel for one another. We have to put that in front of all the laws and borders and different political stuff.
You can watch a video of the press conference below: