The poster of the film, directed by Kabir Khan, features the leading pair blindfolded with tri-colour in the backdrop of burning Mumbai's iconic Taj Mahal Hotel.
Unveiling the first look, Kabir tweeted, "Here it is... PHANTOM first look."
This is the second time Saif, 44, is teaming up with the "Ek Tha Tiger" actress after "Race".
"Phantom" is an upcoming Indian political thriller film, produced by Sajid Nadiadwala. The film is slated to be about the post-26/11 attacks in Mumbai and global terrorism and is an adaptation of book "Mumbai Avengers".
Kabir's latest film "Bajrangi Bhaijaan" is currently in cinemas.
"Phantom" will hit theatres on August 28.