Valtteri Bottas knows he must earn longer Mercedes Formula 1 deal

Both Bottas and team-mate Lewis Hamilton are now signed until the end of 2018, ensuring Mercedes and its drivers have maximum flexibility in the potentially busy '19 driver market.

While Bottas's strong performances since stepping in at short notice as retiring world champion Nico Rosberg's replacement at Mercedes meant he was long expected to keep the seat, the length of his new deal had been a question mark.

"I have to say I'm happy with this," said Bottas of his one-year contract.

"I understand of course always the team's view on things, and for sure the team also wants to have options open for the future.

"I understand 100%, but with this I am very happy. It's still better than the original contract that I had.

"It's still as always before with my career in F1, it's going to be completely down to me.

"If I perform well, there's going to be no problem, and we can have a long future together.

"I believe in myself, I believe I'll continue to grow as a driver and be a better driver.

"Even this season already, I was given this one-year opportunity to make it for a second year, so that gives me confidence."

Bottas insisted he had never had any concerns about losing his seat in 2018.

"There's been no point honestly in the season where I've been in a massive panic about it," he said.

"The season started pretty well, we've got some good results together, and at no point during the year so far have I got any signs from the team they were looking somewhere else.

"That's why it's not like a massive difference, the feeling, but obviously it's all positive."

He admitted that this time around negotiations were very different, after the rush to release him from Williams earlier in the year.

"For sure in January, when I did the contract for this year, only eight months ago, it was a very different situation," Bottas said.

"Of course I was always going to agree to anything to be able to drive the quickest car, so it was a very different situation and everything had to be done quite quickly."