Red Bull do not intend to renew their contract with Toro Rosso driver Daniil Kvyat for 2017, according to a report.

Earlier, officials including Dr Helmut Marko and Franz Tost sounded upbeat about the young Russian's future, but a source close to the team has given Russian news agency Izvestia a different account.

"Red Bull had hoped the return to Toro Rosso would embolden Kvyat, relieving the pressure on him," the source is quoted as saying.

"It was expected that he would score points regularly and become an example for [Carlos] Sainz.

"But in the last seven races, Daniil appeared very uneasy against his teammate, and the most recent setbacks seem to have finally convinced Helmut Marko to not renew the contract."

The report adds that Frenchman Pierre Gasly seems first in line for the seat, with 22-year-old Kvyat reportedly on Williams's 2017 shortlist.

Red Bull declined to comment.