However, the Italian concedes that Manchester United's history of success means that they are still seen as the best team in the country.
Mancini said: "For the last 20 years Manchester United have been winning constantly.
"Playing often against United has helped our progress and allowed us to learn. We've moved closer to them but they are still better than us.
"They have more experience and that team spirit that we are in the process of building here."
The 47-year-old has been in charge at Eastlands since 2009.