The Chile international, who is likely to be sidelined for another month with a knee injury, has endured trying times since his move from Arsenal in January 2018.
He has managed just five goals in 41 appearances for the club, with only two in 23 in this current injury-troubled season.
But with the team’s fortunes transformed since caretaker manager Ole Gunnar Solskjaer replaced the sacked Jose Mourinho in December, Sanchez is looking towards a better future.
“I want to keep showing my love for football. I know what I can do. I have belief in my ability,” he told.
“United are such an important club, not only in England but on a global level, and I would love to help bring a trophy to the supporters.”
“Obviously, I want to make the United fans really happy,” the 30-year-old added. “I want to score goals. I want to bring them joy. I want to win silverware.
“When we lost last year’s FA Cup final to Chelsea, I was not happy. Not happy at all. In fact, I was sad because I just wanted to make our wonderful supporters happy. I saw the fans who had come to pack out Wembley Stadium. They were all around me — all red. I liked it. Wembley was all red.”