He said: "My future is with Arsenal and I am very happy to stay there. Everyone treats me very well in London and I have no reason to leave.
"I will never play for a club where I am not comfortable with the manager. It is true that Arsene Wenger has helped me a lot and I can only thank him for everything he has done for me.
"I owe him a lot but if I want to stay at Arsenal, it is because I have trust in the team and I am comfortable to stay there.
"I feel very important there and the day that changes will be when I want to have a new club. I don't know if I will return to Spain. It is very difficult at the moment. I am 21 and have grown as a person in London.
"I want to continue living here and not risk losing leaving all the things which suit me so well. I feel important at Arsenal and have a lot of responsibilities in the team.
"I feel we can do very well next year and will try to produce my best form at the start of the season. We want to win the Champions League."