Gasly, who currently sits second in the GP2 Series standings, was a prime candidate to partner Carlos Sainz at STR in 2017, but was ultimately overlooked as Red Bull opted to retain Daniil Kvyat for another year.

For the 20-year-old Frenchman, that decision came as a surprise, Gasly saying the situation had developed "very quickly".

"Of course, I was a bit surprised. Things were looking pretty good, and suddenly, everything went very quickly and they signed Daniil very quickly," Gasly told Motorsport.com.

"I was a bit surprised and didn't really understand why. That's how it is. We know sometimes with Red Bull everything can go very quickly.

"We saw that with the decisions they made in the last two seasons. Now it's done, so I need to move forward."

Asked about Red Bull's explanation for the decision, Gasly said: "They didn't really explain it to me. That's why I don't really understand.

"They just told me that they have some reasons why they did it and why they kept him [Kvyat] in the team. That was about it, I don't know much more.

"I talked a lot with Helmut [Marko] in the last two days and we're going to try to see what's best… he knows my goal, he knows I want to get into F1 and that's really my target, so I need to look at the options and see what's best to achieve this goal."

Gasly, who sits seven points off Prema teammate Antonio Giovinazzi ahead of the GP2 finale at Abu Dhabi, also said it was unfortunate Red Bull's decision didn't wait until the conclusion of the season.

"It's a shame they didn't wait until the end of the championship to see if I was going to get the title," he said.

"It's been a positive season, quite successful so far. Of course, it's never as good as what I wanted. You always want to do better than what you have done, but I think it's been pretty good and if we can grab the title at the end of the year, that would be a good achievement."

Horner: Gasly remains "very valued"

Red Bull team boss Christian Horner, meanwhile, said that Gasly was "very valued" by the energy drink giant and would remain in its future plans.

"He will remain a part of the team," Horner said.

"Obviously his priority is to try to win the GP2 championship. Again, he is very valued.

"He is conducting good work for us. He did the tyre test last week which is how high we regard him. We are in a fortunate position that we have good talent around us."

Horner said that Gasly's race programme for next year remained unclear, but also confirmed: "For Red Bull Racing, he will be test and reserve and conducting a lot of simulation work - and whatever else comes down the pike."

Interview by Erwin Jaeggi

Additional reporting by Jonathan Noble