Inter have made an inconsistent start to the 2014-15 campaign and sit ninth in the Serie A table with 16 points from 11 matches.
The San Siro club's spluttering form has led some to suggest that Thohir's patience with Mazzarri could be wearing thin, but the Indonesian insists he has not put any undue pressure on the coach.
"I've never given him an ultimatum, although I've read several times that I have," he told La Repubblica.
"I've said the same thing six or seven times, and I'll say it again - I started this project with Mazzarri, and he can feel comfortable, we know that bringing a plan to fruition takes time.
"But at the same time you must also get results. We have a lot of injuries, which has hurt us but the team is good."
Inter, who drew 1-1 at Saint-Etienne in the UEFA Europa League on Thursday, host Verona in the league on Sunday.
