Mancini praises United success
City officially surrendered their crown on Monday as Alex Ferguson's side romped to a 3-0 success against Aston Villa that saw them clinch their 20th top-flight title.
Although Mancini's men have a game in hand on their rivals, they are 16 points adrift of the champions with just five matches to play, despite sitting second, indicating the ease of United's triumph.
"They deserve to win this title because they won a lot of games in a row. The crucial moment was when we played QPR, Liverpool, Southampton," Mancini said.
"That moment we had big problems with our players injured. We lost key points. United have more attitude than us, as a club, as a team.
"They did better than us, they won a lot of games in a row, it was really difficult. We should be also realistic. If there is one team that did better than you, you can do nothing.
"They deserve to win this title, many congratulations to Manchester United for the work they did this season."
When asked why City had failed to win back-to-back Premier League titles, Mancini lamented the club's work in the off-season transfer market and admitted they had missed out on several targets.
"[By now] we should have our targets in mind. You should move very quickly. We didn't do this last year. We moved so slowly. We lost the players that were our targets to improve our team."
Mancini knows keeping his stars focused for the remainder of the season will 'not be easy' but he has demanded a strong finish, starting with Saturday's home fixture against the in-form West Ham.
He also praised outgoing defender Kolo Toure, who this week announced he will be leaving the club after not being offered a new contract at the Etihad Stadium.
"He [Kolo] is a good guy, a serious professional player and fantastic man," he said.
Mancini was also quizzed on the 10-match ban handed to Liverpool forward Luis Suarez for biting Chelsea's Branislav Ivanovic on Sunday.
He said: "Sometimes they [FA] take a strange decision for me. If you want my opinion, this is strange. Ten games I think is too much…I don't know if this is worse than other tackles or situations.
"I think that five [or] six games was enough."