The Frenchman completed his move to City last week.
Nasri was asked about why did not extend his contract at Arsenal last year, but explained to L'Equipe: "Why didn't I extend at Arsenal last autumn? They made me an offer and my advisers made another one.
"In this last one there was a clause that Arsenal officials didn't really accept.
"Then, it lasted. When they came back to offer me again in June, I made my decision. In my mind I wanted to leave, above all after the very difficult end to last season and I also already had nice contacts.
"At first Arsene Wenger wanted to keep me. Then, both clubs needed time to agree a transfer fee.
"My agents worked well. With the lawyers they wanted everything to be in order. When the transfer is big, you have to be patient. I am also happy Arsenal could get a nice fee. I prefer to leave that way than being a free agent. I did the same at Marseille. But that 28million fee doesn't put me under any pressure."