Speaking to Sky Italia at the Gran Gala del Calcio, the Inter captain addressed speculation that placed him in Barcelona's sights once their pursuit of Julián Álvarez collapsed during the window.
"When these offers and these calls come in, it's always a pleasure, because you work to stay at the top," Martínez said. "The rumours were true, but I have very clear ideas: I wanted to stay here with my team-mates and this magnificent support.
"I would stay forever, and as long as they want me, I'll stay here. But in this job we already know: when you're no longer useful, they let you go. Inter is everything to me: pride, happiness and the desire to keep going.
"I chose to stay here again, I want to do great things at Inter."
The 29-year-old Argentine enters the new season on the back of finishing runner-up at the World Cup with Argentina, lifting another Scudetto as Inter captain, and scoring 22 goals in all competitions last term. He said the scale of what he has achieved at the club continues to surprise him.
"I never imagined reaching this point in my career with Inter, achieving all my goals," Martínez said. "This motivates me to keep going; it's my mentality. I try to give everything in every training session.
"In football, you never know what's going to happen, but today I have a contract and I'm happy. I decided to stay because I feel good and I want to do great things at Inter."
Martínez is contracted to the Nerazzurri until June 2029, and the club has made clear it has no intention of losing its captain at any price.
His comments represent the first time the striker has spoken publicly since the transfer window closed, and confirm that interest from Barcelona was substantive rather than speculative, even if it never advanced beyond contact between the two parties.
Inter Milan's decision to hold firm on their captain reflects his central importance to Cristian Chivu's side both on and off the pitch, particularly after a summer in which the club made no secret of their reluctance to entertain any departure involving their leading forward, regardless of the figures being discussed elsewhere in the market.