The midfielder, who joined Stuttgart from Augsburg in 2011, will be out of contract with the German outfit at the end of this season.
"We are out to keep Ibo at our club. We have had talks with him and his agent. We have told them our point of view," he told Bild. "Up to now, we have not yet reached an agreement on a new contract."
The 25-year-old has made 11 international appearances for Guinea.