The Argentina international's five-year deal at Etihad Stadium takes him to the end of the 2018-19 season.
He has scored 128 goals for City since signing from Atletico Madrid for £38m in 2011, winning two league titles.
Aguero, 27, told an Argentine radio station that "it's clear" he is going to return to his first club Independiente "and retire there".
"Here (at City) they know what I want to do, they know I want to return to Argentina," he added.
"My family know that I am going to go there when my contract with Manchester City finishes in 2018."
It is unclear why Aguero referred to his deal ending in 2018, as the club have confirmed he is contracted until 2019.
Manchester City striker Sergio Aguero has said he will leave the Premier League club when his contract expires.