The former Atletico Madrid striker has been regularly linked with a return to Spain since moving to the Etihad Stadium in 2011, with his goals helping City to two Premier League titles and the Capital One Cup.
However, Aguero - who is currently at the World Cup with Agentina - maintains he is not interested in a move to either of the Spanish giants as he is settled with the Premier League champions.
"There's lots of talk about Real Madrid and Barcelona. It's always the same every year," he told Spanish radio station Cadena Cope.
"But the truth is that I'm going to stay at City. I'm very happy and I'm going to continue there."