The Brazilian has been linked to Barcelona this summer, but he says he will see out his contract at Parc des Princes unless the club want to sell him
The 28-year-old has been regularly linked with a transfer to La Liga champions earlier in the close-season but reports in late July suggested he had put pen to paper on a new contract at Parc des Princes.
The Brazil international has insisted that he has no intention of leaving the French capital in the near future unless PSG decide they do not want him any longer.
"It is my responsibility to stay in Paris and fulfil my contract until the end," he told reporters on Wednesday. "There was some speculation about Barcelona, if I would go or not.
"But I always make it very clear. I'm very happy here and I want to stay. I believe in the project, even after the departure of Carlo Ancelotti and Leonardo, nothing has changed.
"And my decision to try to leave is not true. I was very clear with our president, I said: 'I will stay until the last day of my contract.' Of course, if PSG say to me 'look, Thiago, we don't want you any more', it would be different.
"But I'm very sure I will stay till the end of my contract and I'm very calm about this."
The centre-back struggled with a hamstring injury last season, restricting him to just 22 Ligue 1 appearances in the process, but he says he has been working hard to ensure he does not have similar problems in the new campaign.
"I started a project with PSG and my physiotherapist to have a different season," he continued. "Last season I had many injuries and I didn't play as much in case I risked another problem.
"It was a difficult year for me. This season I reflected on my mistakes and decided to do something different, I want to be better prepared to be able to play well at the top level without injuries."