"Sometimes work takes you away from moments that you really wish to be part of... like tonight Mr Bachchan's 70th B'DAY celebration," tweeted Dia, who is in Jakarta for some work.
Amitabh turns 70 on Thursday, but a special, star-studded celebration with the Who's Who of the film industry was organised on Wednesday night.
Dia finds the veteran actor "a great inspiration".
"My most memorable film with him is Shoojit Sircar's film (Shoebite). Can't wait for you to see it. Epic performance. The amount of work he packs in, his dedication, commitment and love for the craft is just unparalleled. RESPECT," she added.