The 26-year-old Montenegrin player moved to the San Siro on an 18-month loan deal last summer.
According to MailOnline's Simon Jones, in the terms of the deal struck between the two clubs, Inter were obliged to make the move permanent upon Jovetic making his first appearance for the Nerazzurri in 2016-17.
With the forward having made a substitute appearance in Inter's 2-1 defeat of Pescara on Sunday, Inter must now pay City just over £12 million for a player who originally cost the Sky Blues £22 million to sign from Fiorentina in 2013.
Per Jones, Inter attempted to offload Jovetic back to the Florentine outfit over the summer to avoid having to pay City the transfer fee, while "Premier League clubs also showed interest" in the forward.
The original announcement of Inter signing Jovetic back in July 2015 said that he had signed a four-year contract up to 2019.
In his first season with the club Jovetic played in 26 Serie A matches under manager Roberto Mancini, netting six goals and providing two assists, per WhoScored.com.
In 2016-17, though, with Frank de Boer now in charge at the San Siro, the 26-year-old has played only 16 minutes of top-flight Italian football after three matches of the campaign.
Jovetic was also left out of Inter's UEFA Europa League squad—they begin their Group K campaign against Hapoel Be'er Sheva on Thursday.
He was clearly unhappy to not make De Boer's squad for the European competition, but is still holding out hope of being included if Inter make it to the latter stages, per Premium Sport (via Football Italia):
I’m disappointed, but there are four of us so I’m not alone. We hope that we’ll get past the group and then other players can be added to try and win the Europa League.
A transfer? I wasn’t close to Milan, while with Fiorentina there was contact between the two clubs. In the end they didn’t sell me, and I want to stay at Inter and play because I know I can play.
Now that Jovetic has been confirmed, once and for all, as a permanent Inter player he can focus solely on becoming a key part of the first team.
Jovetic has endured three disappointing seasons since moving from Fiorentina to City, but he is in the peak years of his career and could be valuable at Inter if he finds form.