Hungary - Jenson Button is not so sure McLaren-Honda can be in a winning position as soon as 2017.
His team mate, Fernando Alonso, is already under contract for next year and he says the target is not only wins but the world championship.
Competitiveness deciding factor
Briton Button, 36, insists he is in control of his decision regarding 2017, saying he needs a more competitive car.
He is quoted by Auto Motor und Sport in Hungary, saying: "We have made progress. But you always want more.
"None of us are happy about where we are. We want to win.
"Every driver here thinks about his position and whether there is a possibility in the future to win. If not, you have to go somewhere else."
Realistic about winning chances
"We simply don't have the best car," Button added. "We're working on it, but whether we can fight at the top next year remains open."
He said the top ten in Hungary will be difficult for McLaren, but predicted a strong weekend for Red Bull.
"They have a good chance to win here," said Button.