"A good first season for me would be to qualify for the Champions League or to win a trophy," he said. "We will fight for the league title all the way and try to win the other competitions but the target is to finish in the top four.
"Within two or three years it will be normal for City to be playing in the Champions League every year, so I hope we can be on a par and challenge the best clubs around the world.
"I enjoyed six years at Valencia, they discovered me as a footballer and they will always be a special club for me. But the time was right to seek a new challenge and I am thrilled about how things have gone so far.
"The league here is one of the best in the world and I desperately want to bring success to City and win trophies.
"It's true that the game here is a lot faster than in the Spanish league. La Liga is more tactical - we like to move the ball around quickly and pass often - but in England they like to fight and run hard.
"One thing is for certain, over the last few years City's image has grown massively in Spain. The project here is getting more important with every year. It's very exciting that I'm now part of it."