US intelligence agencies are bracing for more revelations and controversy as Edward Snowden, the National Security Agency contractor who leaked a treasure of secret documents in 2013, is about to release his memoir, the New York Times reported.

The publisher, Metropolitan Books, is releasing “Permanent Record” in the United States, though it will be published in more than 20 countries, including Britain and Germany, on Sept. 17.

Financial details were not disclosed for a book that was itself a covert project, quietly acquired a year ago by Macmillan and identified under code names in internal documents.

“Permanent Record” discusses how Snowden helped create a system of mass surveillance the NSA used to collect information on millions of US citizens and others, as well as the “crisis of conscience” that led him to rebuke the system he helped create.

Snowden consulted with several people on the structure of the book but wrote it himself, the spokeswoman said.

In a video posted to his Twitter account this week, Snowden expressed regret for his role at the NSA.

“Everything that we do now lasts forever, not because we’d want to remember, but because we’re no longer allowed to forget,” he said. “Helping to create that system is my greatest regret.”

The video also notes that the book’s Sept. 17 release date is Constitution Day, which recognizes the date the United States’ foundational document was signed in 1787.

From his exile in Moscow, Snowden has become a bit of a pop culture icon, praised by some, hated by others.

He has been widely condemned by intelligence officials, who claim that Snowden has caused lasting damage to national security, and defended by civil libertarians and other privacy advocates who praise Snowden for revealing the extent of information the government was gathering illegally.

In 2014, The Guardian and The Washington Post shared a Pulitzer Prize for their reporting on Snowden.

He’s also the subject of “Citizenfour,” an Academy Award-winning documentary directed by Laura Poitras, and in the Oliver Stone movie “Snowden.”

He likely won’t be able to make public appearances to promote the book, but may appear in further videos. Snowden said he would love to come back to the US and face a fair trial, but there is “no fair trial available” to him at the moment.

“Edward Snowden decided at the age of 29 to give up his entire future for the good of his country,” said Macmillan chief executive John Sargent. “He displayed enormous courage in doing so, and like him or not, his is an incredible American story. There is no doubt that the world is a better and more private place for his actions.”