Kaif was expected to head straight to Chicago to prepare for stunt sequences for Dhoom 3 with Aamir Khan after completing the shoot in Ladakh; however, this has apparently been delayed at Shah Rukh's request.
A source told The Times of India: "Katrina, who left for Ladakh today, was supposed to shoot for two weeks with Shah Rukh and then head to Chicago. But now on SRK's request she's staying back until the first week of September.
"SRK wants her to be a part of the schedule even when he's shooting solo. That way he feels he would be better able to focus on the complicated scenes."
Kaif and Aamir have been unable to rehearse their stunt sequences for Dhoom 3 due to their conflicting schedules. It's the first time the two actors have been cast opposite each other in a film.
A source close to the Ek Tha Tiger star said: "The original plan was to have Kat and Aamir practice all their stunts together. That's how Aamir willed it.
"But unfortunately the two never got around to exchanging anything more than courtesies. Now there's no time. When Katrina joins Aamir in Chicago, it's straight for the camera."
With both films being produced by Yash Raj, it was reported that the trailer for Dhoom 3 will be screened along with the Yash Raj romance.
New images of Shah Rukh Khan from the untitled film, in which he reportedly plays an army officer named Samir, have also been released.