Scuderia Toro Rosso has confirmed Pierre Gasly and Brendon Hartley will form its Formula 1 driver line-up for the 2018 season.

Gasly and Hartley have a combined seven grands prix of experience between them, having both been drafted in by Toro Rosso late in the 2017 campaign.

2016 GP2 champion Gasly made his F1 debut in Malaysia in place of Daniil Kvyat, while Hartley was drafted in as a one-off replacement for Gasly in Austin due to a Super Formula clash, only to then retain his seat for the remainder of the season.

Toro Rosso F1 team boss Franz Tost previously said it was "likely" both drivers would remain for 2018, with confirmation arriving on Thursday ahead of next weekend's season finale in Abu Dhabi.

"We're really happy to have Pierre and Brendon confirmed so early by Red Bull as our drivers for 2018," Tost said.

"During this last part of the year they've shown that they're ready for Formula 1, getting to grips with the car quickly, showing good performances and always demonstrating to be prepared for the challenge. We have been truly impressed by both their steep learning curves.

"As we know, F1 is something that not all drivers can adapt to this fast! Therefore, we're looking forward to having a full year with them; one where we can hopefully provide them with a good package which, combined with driver consistency, can surely put them in the best possible situation to deliver.

"I'm sure they will keep pushing hard and fight for strong results, together with the team."

"I'm super happy to race for Scuderia Toro Rosso in 2018, for my first proper season in Formula 1," said Gasly.

"I would like to thank all the people involved, who helped me get here: Red Bull, Toro Rosso, my family and all the ones who have supported me in the lower series.

"I'm really excited and super motivated to give it my all in Abu Dhabi and the whole of next year! I just can't wait!"

Hartley, who will make his final appearance with Porsche in the FIA World Endurance Championship this weekend in Bahrain, was also pleased to have his full-time switch back to single-seaters confirmed.

"It's really amazing to be confirmed as a Formula 1 driver for next year with Toro Rosso – It's very satisfying to have converted an opportunity that came as a surprise into a 2018 F1 drive, I couldn't be happier!" Hartley said.

"I'd like to thank Red Bull and Toro Rosso for believing in me and giving me this second chance – dreams can come true.

"I'm now going to carry on working harder than ever in order to finish this busy end of season on a high and start the new year as strong as possible."