Marathon runner Guor Marial will be in a unique position when he takes to the starting line on Sunday. He will not be running for any country - instead simply running under the Olympic flag.
The unusual situation came about as Marial is a refugee from civil war South Sudan, who has been living in the US for the last 12 years but doesn't have citizenship.
Although South Sudan has recently achieved its independence, it has not yet established an Olympics Committee.
Speaking to reporters, Gour said: "Being under the Olympic flag is a great feeling it is something, a lot of people don't get that opportunity, so I feel fortunate, representing the five rings is the best thing, so I am representing the whole world basically. Thank you."
He added his family will be watching him: "The last time I saw my family was 1993. So mathematically, it is almost 20 years.
"In terms of whether they would watch me on TV, yes they will be able to watch me on TV. There is a local city, I would say it is about 30 miles, 60km, 50 to 60 km from where they live.
"They will walk there. At the moment in South Sudan, it is the raining season so there is no vehicle, plus there is no official road where the vehicle can go to the village area, so they will be able to walk to the nearest city, and they will be able to watch me on the TV."