Security has been told to keep the "Twilight" star away from the red carpet and after-party of Pattinson's first scheduled public appearance on August 13 at the New York City premiere of "Cosmopolis," reported Radar Online.
The couple have fallen apart after Stewart admitted to hooking up with her "Snow White and The Huntsman" director Rupert Sanders after photos were published of the pair making out.
At the time, Stewart released an emotional statement apologising for cheating on Pattinson.
"The decision was made because Robert just doesn't want to see her. There were fears that she could use it as a chance to talk to him in person and that sort of drama is not wanted at the premiere," a source said.
"There's also the fact that if she did attend, it would distract from the film premiere itself and the movie bosses are not interested in that sort of publicity," the source added.
Yesterday, it was reported that Sanders' wife Liberty Ross has told him that he won't be directing the sequel to "Snow White and The Huntsman" if he wants to save their marriage.
Sanders, 41, was originally lined up to direct the sequel after it became a box office success. However, he is yet to sign an agreement with Universal Pictures who are considering putting someone else in the director's chair.