Toro Rosso principal Franz Tost has admitted that they are keen to retain the services of Carlos Sainz Jr and Max Verstappen, assuming the Red Bull sister team remain in Formula 1.

With doubts over whether Red Bull and Toro Rosso can secure an engine for next season, the position of the Italian-based constructor is still uncertain.

However, Tost is in no doubt as to who will be his drivers, if they stay on the grid.

"If the team is on the starting grid then I consider that both of them will be the drivers of Toro Rosso," Tost told reporters.

"So far they have done a very good job and of course we want to keep them."

Toro Rosso are believed to be close to securing an engine deal with Ferrari, while Red Bull could perform a U-turn and stick with a Renault power unit.