The Argentine striker has been in the city putting the finishing touches to his ?38million move.
And he tweeted: 'I'm already a City player. Happy to be in this club and this city. Thank youall for the welcome and the reception!'.
New boy: Sergio Aguero (left) meets fans at the Etihad Stadium after arriving to complete his move
The club are yet to confirm the deal but the former Atletico Madrid man is expected to sign a five-year deal worth around ?200,000 per week.
The23-year-old, who is second only to ?50m-man Fernando Torres in terms oftransfer fees in the Britain, arrived in Manchester by plane on Wednesday morning after enjoying some extended rest in his homeland following the Copa America.
Upon arrival, he tweeted: 'Just landed in Manchester to finalize the details of the offer with the City. Everything is fine! In a while I'll tell you more.'
Sign here: Aguero signed autographs for waiting fans after he arrived at the club's HQ
City are expected to lose Carlos Tevez in the coming weeks and with doubts remaining over the reliability of Edin Dzeko and Mario Balotelli, Mancini needed a proven goalscorer before the Barclays Premier League season begins in two-and-a-half weeks.
Aguero, who played alongside Tevez during Argentina's doomed Copa campaign, will be allowed some holiday before beginning his new life at the Etihad Stadium.
Tevez has been told to report back for training with Mancini's squad on August4 and the same will apply to Aguero, meaning neither player is expected to start in the Community Shield against neighbours and rivals Manchester United three days later.
Blue move: Aguero has just returned from representing Argentina in the Copa America
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Source: Daily Mail
Source: Daily Mail