Jenson Button had other F1 offers for 2017 - Ron Dennis

The 2009 world champion has been a key player in the 2017 driver market with Williams among the teams believed to have been interested in his services.

But following talks with McLaren chairman Dennis, he will stay at McLaren with an option to return in 2018 should Fernando Alonso not extend his current three-year deal.

"Jenson had offers to drive next year in other teams and declined those offers," said Dennis.

When asked what the factors were for taking up the option on Button in 2018 and whether he can race for another team should McLaren not do so, Dennis was coy.

"I can't give you straight answers to those questions, the reality is we'll see where we are in a year.

"We'll get there and then we'll decide if we're going to exercise it [the option] or not.

"But at that point Jenson has to step into the situation with all the right motivation, focus and everything - so it's not a one-way decision.

"What is clear though, is if Jenson's going to drive a Formula 1 car in 2018 I believe it can only be a McLaren.

"I don't think Jenson has a desire to drive anybody else's car."

Speaking early in the Spa weekend, Button confirmed he had options "outside of McLaren next year".

VANDOORNE IN PERFECT POSITION

Stoffel Vandoorne, who takes over the race seat, admitted he has "big shoes to fill".

"Stepping into Jenson's seat is not easy as a young driver but I'm totally up for a challenge," he said.

"Both are world champions, I've been in a reserve driver position this year where I've been following them on track from a very different position.

"I've been learning a lot from how they push a team forward, how they help with the development, and having all three of us pushing this team forward we could be very successful."

Button believes Vandoorne is in the "perfect" position to step up.

"If you look at what Stoffel has achieved in the lower formulas, he's definitely a stand out driver coming through," said Button.

"He's also been well-educated in the world of Formula 1.

"Being third driver here and learning from two world champions, it's the perfect position to be in jumping in a Formula 1 car.

"I know he's determined so we'll see how it goes."