The prolific Colombia striker signed a one-year extension to his deal on Sunday, pledging his future to the Portuguese giants until July 2017, with the new terms including a substantial release fee.
Martinez is reported to have attracted interest from the Premier League, with the likes of Arsenal linked heavily with the player.
But chairman Pinto da Costa revealed that the clause will not be active for the current transfer window or the next one in January and reiterated that Porto have no intention of selling their prized asset.
"Two days ago, when he came back to Porto, we talked and he said, to me, to [director general] Antero Henriques, and to the coach [Julen Lopetegui], he wanted to stay in FC Porto, he wouldn’t move and was willing to renew his contract," Da Costa told the club's official website.
"After that, we set up a strategy and decided how we were going to handle the renewal.
"In the agreement we signed, we decided on three more years of contract and determined that the release fee won't take effect for this current transfer window or for the January one.
"Whoever wants him, will have to talk to FC Porto. Those that went around stating Jackson would go here and there need to accept what I’ve always said: Jackson is staying in FC Porto."
The 27-year-old, who has netted 60 goals in all competitions in two seasons with Porto, is now ready to focus on football ahead of the new Primeira Liga season.
"I feel good here, I have good relations with the club and with the fans," he is quoted as saying by Corriere dello Sport.
"I love the city and I am ready to give my best."
Porto, who finished third last season, begin the 2014-15 campaign with the visit of Maritimo on August 17.
