City have fallen three points behind United.
He said: "Why wait until next season if we can win it now?
"I can promise you that we'll be fighting until the very end. We all want to make it and though it won't be easy, we believe we can win the Premier League this season.
"Winning titles is about never giving up and we will never give up. I want to win it this season and then many more with City after that."