Sebastian Vettel is open to a return to Red Bull after only holding preliminary talks with Renault before they signed Fernando Alonso.

Four-time Formula One champion Vettel will leave Ferrari at the end of the season and is without a seat for 2021.

The German won all of those titles during an illustrious six-year spell with Red Bull and would be interested in returning and teaming up with Max Verstappen next year, with Alex Albon's place in the team yet to be confirmed.

"I think it's a winning car," Vettel said when asked on Thursday ahead of the Styrian Grand Prix if he would be interested in going back to Red Bull.

"I'm here to compete and I'm here to win, so probably the answer would be yes."

He added: "I know why they were strong back then and they are still, I think, a contender and obviously it's a car that you can win races in. So for sure that would be interesting."

With his future up in the air, Vettel acknowledged that carrying on, having a break or retiring are all on the table.

He had discussed a potential switch to Renault, who had a 2021 spot vacant due to Daniel Ricciardo agreeing to join McLaren, with Carlos Sainz heading to the Scuderia.

However, Alonso will return to the French team, with whom he won back-to-back titles in 2005 and 2006, after a two-year break from F1.

Asked if he spoke to Renault, Vettel said: "Yes I did, but obviously at no point concrete enough or fundamental talks or real talks.

"As you've seen as well, they've gone a different direction. It doesn't change much for me. It really depends on my decision, which I'm not pressured to take in the next couple of days. I want to take the time that I need to decide.

"I'm generally of the conviction that, if you want to win, you have to be happy to take on anyone. I'll take the time that I need to take a decision for myself first.

"Everything is an option at the moment: carry on, have a break, or retire. It depends on what sort of options are around."