Toro Rosso wants current-specification Formula 1 engines for 2017

The outfit did not complete its F1 engine deal for 2016 until just before last year's season-ending Abu Dhabi Grand Prix, and it could only secure Ferrari's end-of-'15 unit.

The delay was caused by both Red Bull-owned teams requesting to end their deals with Renault at the end of 2015, and then being left without a power supply.

This year, Tost believes Toro Rosso is in a better position to get a deal sorted.

"We have to get the same specification," he told Autosport.

"Because of last year's late decision, we were in the corner and we had to take what was offered to us.

"This year, we're in different situation. We want the same spec next year."

A manufacturer can request to supply a previously homologated engine providing it can prove to the FIA the power unit can "fairly and equitably be allowed to compete with the other homologated power units".

It is currently unclear what manufacturer will supply Toro Rosso next season.

Under new-for-2017 rules, manufacturers had until May 15 to inform the FIA of the supply deals it had in place.

If a team was left without a power unit for next season following that submission, the FIA will move to find a solution before the next deadline of June 1.

A ballot will be organised to arrange a supply if no agreement is made by that deadline.

Tost said he was pleased with the performance of the year-old Ferrari power unit so far this season despite disappointing results that have left it fifth in the constructors' championship, 39 points behind fourth-placed Williams.

The team's best result is a pair of sixth-place finishes, one with former driver Max Verstappen in Bahrain, the other with Carlos Sainz Jr in his home Spanish Grand Prix.

"We're quite happy with the performance of the engine," he said.

"From the performance side, Ferrari provides us with good material."