The 28-year-old, who made his Formula One debut for Williams in 2013, is currently standing at the third post in the driver's championship after posting two victories and eight podium results this season.
He is lagging just 41 points behind leader Sebastian Vettel of Ferrari and 34 points behind his Mercedes teammate Lewis Hamilton.
And Mercedes boss Toto Wolff insisted that it is a no brainer to continue with Valtteri.
"We want to keep him," Sport24 quoted Wolff as saying.
Wolff, who was speaking ahead of this weekend's Italian Grand Prix, also quashed speculations that Bottas still needs to prove his worth.
He said, "We are very happy with Valtteri. We want to keep him in the team."