The Spaniard and teammate Charles Leclerc are under contract with Ferrari until the end of 2024 and Sainz has made it clear he wants to have his future sorted going into next season.
Sainz has continued to find himself linked with a switch to Audi in recent months despite repeatedly insisting his sole focus is securing a new deal to remain with Ferrari.
The 29-year-old has claimed the only non-Red Bull victory this year by winning the Singapore Grand Prix and currently leads Leclerc in the drivers’ championship.
"For me that was never a doubt,” Sainz replied when asked whether his win had cemented his confidence and belief in Ferrari.
"I think there's never been a doubt that I'm very comfortable at Ferrari, that I want to be here for the medium to long term.
"Also, the fact that there was always high confidence between each party. For me, the wins and podiums, the only thing they do is reassure everything that we already knew.
"I hope that the winter is a good opportunity to find an agreement and continue working in the future because it's the place that I love driving for, and see myself driving and trying to help a world championship soon.”
Speaking in August, Ferrari team principal Fred Vasseur confirmed talks over a contract renewal would take place with Sainz before the end of the current campaign.
“I think that with Carlos, we are fully aligned,” Vasseur said. “We have [been asked] many times the same question. We always give the same reply, that we have time to discuss, that we have still 18 months of contract in front of us.
“We both want to start the next season with a clear situation. It means that we have to take action and a decision before the end of this season.
“We have still four or five months in front of us to decide. But we are fully aligned on this point with Carlos and his management, and we will have the discussion soon.”