The Italian boss has been at the centre of speculation that he could be given the boot if his side fail to knock Leeds United out of the FA Cup in the fifth round on Sunday.
"We started our project three years ago," Mancini said in a press conference. "In three years we are always on the top. We fight for the title, we have won three trophies, we have the chance to win more this year.
"All the people who talk about this don't understand football. If Manchester City should sack me, the other 20 teams in the Premier League should be without a manager."
City, who won the Premier League title in dramatic fashion last season, are currently 12 points behind leaders Manchester United in the table.