Smith was one of four out-of contract players to be offered extended stays at the County Ground, while 13 were released.
Craig Easton, Lescinel Jean-Francois and Patrick Kanyuka are the other Robins who have until June 15 to make a final decision on their respective offers.
Smith told the Swindon Advertiser: "There's no real reason for me to go anywhere else. It's just one of those things that I haven't signed the contract yet.
"Hopefully I will sign. I've got until the middle of June to do it. I haven't spoken to anyone else and I don't see any reason why I won't sign."