Tom Hanks and Meryl Streep are in talks to star in a film directed by Steven Spielberg about the Pentagon Papers.
The Post will tell the story of the Washington Post's legal battle to report a damning classified study about America's role in the Vietnam War in 1971.
Spielberg has signed on to direct the film, based on a script by Liz Hannah, the Associated Press reported.
Hanks is in talks to play Washington Post editor Ben Bradlee, while Streep would play the newspaper's publisher Katherine Graham, according to Deadline.
Streep recently defended the freedom of the press in a speech opposing US President Donald Trump at the Golden Globe Awards.
She encouraged people to donate to the Committee To Protect Journalists and criticised Mr Trump's impression of a disabled reporter, saying it "kind of broke my heart".
The Post would mark Spielberg and Hanks' fifth film together after Saving Private Ryan, Catch Me If You Can, The Terminal and Bridge Of Spies.