Vettel has activated a release clause in his contract with the Milton Keynes-based outfit after a six-year spell onboard and looks set to switch to Ferrari, with Fernando Alonso poised for a return to the McLaren team.

Vettel has claimed 38 wins, 44 pole positions, four Drivers' titles and four Constructors' crowns with Red Bull.

"Sebastian has advised us that he will be leaving Red Bull at the end of the season," read a Red Bull statement. "We want to warmly thank Sebastian for the incredible role he has played at Red Bull for the last six years."

Vettel, who said that there will be an announcement over his future "very soon", thanked the Red Bull family.

"It is a big step and hard to make such a decision," said Vettel. "The chance to drive in F1, the first win with Scuderia Toro Rosso, the four championship wins with Infiniti Red Bull Racing and many other great memories have bound Red Bull and myself together into a kind of family. No one can take these times away from us.

"I would like to express big thanks to [Red Bull owner] Dietrich Mateschitz, [team advisor] Dr Helmut Marko, [team boss] Christian Horner, the whole Red Bull family, Infiniti Red Bull Racing and Scuderia Toro Rosso. I would like to thank everybody within Red Bull for their confidence in me, trust and great support over the last years."

Kvyat's promotion ensures that Red Bull's full line-up remains a product of its young driver scheme.