Sanchez said: “I believe that United really are a very big club on a worldwide scale and even more so in England, where they are the biggest.
“They always want to win and to be fighting on all fronts, and that's the reason I wanted to come here.
“I also had some great players alongside me when I was at Barcelona, some highly experienced guys who had great quality.
“I think that United are not too dissimilar to them as a club in terms of their size and their stature.
“Manchester United are a massive club, which always aspires to win big trophies and that is what I'm trying to help make happen.
“I want to try and keep improving so we can see the club winning trophies."
He added: “We still have areas where we can continue to improve.
“And we can do this on a day-by-day and a game-by-game basis.
“I think that every game I've played in up to now I've maybe found it hard to adapt to the style of play.
“And I've also been getting to know my other team-mates.
“I believe we need to improve in all aspects.
“We need to be focused and concentrated in the big games and in the so-called lesser games, too.
“That's what the great sides do.
“And I think United are a great side, so that's what we need to do."