Fernando Alonso admits leaving Ferrari F1 team was very difficult

McLaren has yet to officially confirm Alonso's deal to come back to Woking, while debate continues over whether Jenson Button or Kevin Magnussen should partner the Spaniard, but Alonso has finalised his own terms.

Although Alonso's relationship with Ferrari broke down over the summer, amid his overtures to rival teams and internal restructuring at Maranello, the double world champion said he was sad to be turning his back on the Scuderia after five seasons together.

"It is very difficult to close the door on Ferrari knowing that I will not work in this red colour next year," Alonso said following November's Abu Dhabi Grand Prix.

"That's a very, very difficult decision to make, but I guess that was the same for Felipe [Massa] last year - after a long relationship saying bye-bye to the team.

"But I miss being on the podium, I miss to celebrate with champagne, I miss to celebrate winning races, winning titles, and I think a new project for me will bring that possibility closer.

"Maybe not in one year's time, but in the future I have no doubts I will fight again."

Alonso said it would be tough for any team to topple the dominant Mercedes in 2015, but the Spaniard said he hoped his own results would be better after scoring just two podiums in 2014.

"I think with the Mercedes form this year, it is going to be tough for any team to recover that gap," Alonso added.

"But I hope to do better, and I hope to enjoy some battles, and podium positions, and a better performance."

NOT RULING OUT FERRARI RETURN

Four-time world champion Sebastian Vettel will replace Alonso at Ferrari next year, but Alonso did not rule out returning to the Italian team in the future.

"I went from Renault to McLaren, and then I went back to Renault; I come to Ferrari, maybe I come back to the team," Alonso said.

"It seems the people who work with me give me one door open when it is normally the opposite of what I read - that I am very difficult to work with.

"At the end of the day, the teams I work with I can come back [to], so that is a good sign.

"At the moment it's not an option [to come back to Ferrari], because obviously if you say bye-bye you do not think five minutes later 'I will come back'."