With five games of the season remaining, The Blues are second in the table but six points behind Alex Ferguson's squad.
"It is not easy to close the gap," admitted Ancelotti after yesterday's 3-1 win over Birmingham. "[But] our aim is to win the next five games. We have to try to do everything and then after that, we can see what our position in the table is."
Asked if it was possible to clinch victory, he told the BBC: "In football you have to believe [you can] until the referee whistles the end of the game. The game is not finished yet. Obviously Man Utd has a fantastic advantage, but we have to try to do the best."
Chelsea's remaining games include a derby with Spurs on April 30 and an away trip to Old Trafford on May 8.