Valtteri Bottas had already set the wheels in motion to secure a seat on a rival Formula One team when Mercedes confirmed their intention to extend his contract.

The Silver Arrows exercised an option in Bottas' deal to keep him at the team through the 2020 season on Thursday, following speculation about Esteban Ocon or possibly even Max Verstappen partnering Lewis Hamilton instead.

The Finn can now rest easy knowing his future is secured, yet he acknowledged, speaking to the media ahead of the Belgian Grand Prix, he had been uncertain of what the future might hold heading into the mid-season break.

Bottas even revealed he had looked into other options "just in case" Mercedes decided to promote Ocon, who has been working for the team after leaving Force India but will join Renault next year.

"Going into the summer break, you know in this sport that, if you've not signed, anything can happen," Bottas said.

"When it comes to the driver positions, there are many, many things that the teams look at to make the difference between the choices. The whole situation was very openly spoken about between me and Esteban.

"I had to wait until last weekend. I was thinking about other options just in case. Obviously, you never want to be left between two chairs.

"I was trying to make a plan for something else, but then things started to go the right way and I saw that it was better to commit to this as it is.

"It makes me very happy to know about the future. I don't need to worry about that now. I can just really focus on the job and, unlike the last couple of races, I want to have a strong result here and a really strong end of the year."

Pushed on how far any alternative talks had gone, though, Bottas would not budge.

"Unfortunately, I can't really say much," he said. "That's very private, all the conversations.

"I wouldn't ever say the name of a team or person I've been talking to because I want to keep the trust. People can trust me, so I can't say much.

"I was waiting first for Mercedes to decide, still knowing other things could be possible if, for some reason, we didn't continue. Everything turned out good, I'm happy, the team is happy."

The 30-year-old said he received a congratulatory message from Hamilton when the extension was announced.

"He sent me a message when it was confirmed," Bottas said. "So far we've made a good team and I believe we are going to make a good team in the future as well."