The German has been targeted by Bayern Munich this summer.
Asked if he expected Sane to stay at the Etihad Stadium, the Spaniard said: "Yes.
"The club made him an offer last year. As I said many times, we want people happy to be here. We are going to help him to be the best."We know his potential and what his level is. He has a special quality difficult to find around the world.
"He knows, they all know, it's difficult (to play regularly) because of the quality we have.
"But, at the same time, I spoke to the club 10 times (to say) I want people here to be happy. If they don't want, they go. The desire to have him to be with us is always there."
When asked for clarification on whether Sane would stay, Guardiola said: "I answered the question, and I was really clear."