"They know what I'm capable of here, they know what I can deliver," he told Sky Sports News. "I feel like I'm an asset to the team, but I can't make the decision for them, and I have to respect their decision.
"I've said all along I'd love to be part of it. I've expressed that to the senior management, bosses and the shareholders. Obviously, things are getting tighter in the midfield to get seats, so I have to be content with what I've done, and I believe over the last four races I've done what's been asked of me.
"I don't know what will happen. I've got to wait and see. We can only work in the background in trying to secure my Formula 1 future. We're speaking, and that's all you can do. All is not confirmed yet."
Di Resta is 10th in the drivers' rankings with 48 points.