(CNN) -- The Obama administration is preparing to publicly disclose for the first time a secret memo offering the legal justification for targeted drone strikes on U.S. citizens on foreign soil, multiple administration officials told CNN.
Solicitor General Don Verrilli decided not to appeal the April 21 ruling by the 2nd U.S. Circuit Court of Appeals mandating the disclosure of the memo, and Attorney General Eric Holder agreed with that decision.
The White House was informed Tuesday of the Justice Department's decision.
The memo won't be made public right away. It has to go through a redaction process that will need to be approved by a judge, according to the administration officials.
A redacted version also means that some of the intelligence the administration used to justify the drone strikes will not be made public.
The memo to be released publicly has already been offered to the Senate on a classified basis, a senior administration official said.
The legal explanation for the drone strikes was also outlined by the Justice Department in the dismissal of a lawsuit filed by the father of suspected terrorist leader Anwar al-Awlaki. The administration said in that lawsuit that al-Awlaki posed an imminent threat.
Anwar al-Awlaki was later killed in a U.S. drone attack in Yemen in 2011.
The memo's author, former Justice Department official David Barron, has been nominated to be a judge on the U.S. Court of Appeals for the First Circuit, based in Boston. Several U.S. senators from both parties had called upon the administration to release the memo to the public before Barron's confirmation.
A procedural vote on Barron's nomination is expected Wednesday in the Senate.
The American Civil Liberties Union, which filed a Freedom of Information Act lawsuit for the memo along with the New York Times, said it hopes the release "signals a broader shift in the administration's approach to the official secrecy surrounding its targeted killing program."
"The release of this memo will allow the public to better understand the scope of the authority that the government is claiming," ACLU Deputy Legal Director Jameel Jaffer said in a statement Tuesday.