WASHINGTON — On the eve of a critical Senate vote and under court order, the Obama administration signaled it will publicly reveal a secret memo describing its legal justification for using drones to kill U.S. citizens suspected of terrorism overseas.

Two administration officials told The Associated Press on condition of anonymity that the Justice Department has decided not to appeal a Court of Appeals ruling requiring disclosure of a redacted version of the memo under the Freedom of Information Act.

The decision to release the documents comes as the Senate is to vote Wednesday on advancing President Obama’s nomination of the memo’s author, Harvard professor and former Justice Department official David Barron, to sit on the 1st U.S. Circuit Court of Appeals in Boston.

Sen. Rand Paul, R-Ky., had vowed to fight Barron’s confirmation, and some Democrats were calling for the memo’s public release before a final vote.

Wednesday’s expected procedural vote would allow the Senate to move ahead with a final vote on Barron on Thursday.

Anwar al-Awlaki, an al-Qaida leader born in the United States, was killed after being targeted by a drone strike in Yemen in September 2011. Some legal scholars and human rights activists complained that it was illegal for the U.S. to kill American citizens away from the battlefield without a trial.

Some senators, including Democrats, have called for the public release of the memo before the final confirmation vote. The White House agreed under the pressure to show senators unredacted copies of all written legal advice written by Barron regarding the potential use of lethal force against U.S. citizens in counterterrorism operations.

Until now, the administration has fought in court to keep the writings from public view. But administration officials said that Solicitor General Donald Verrilli Jr. decided not to appeal an April 21 ruling requiring disclosure by the 2nd U.S. Circuit Court of Appeals in New York, and that Attorney General Eric Holder concurred with his opinion.

The release could take some time, since the redactions are subject to court approval. And the administration also is insisting that a classified ruling also be redacted to protect information classified for national security, one of the officials said.

The drone strike that killed al-Awlaki also killed another U.S. citizen, Samir Khan, an al-Qaida propagandist. Al-Awlaki’s 16-year-old son, Abdulrahman, was killed the following month in another drone attack.

The American Civil Liberties Union and The New York Times filed a FOIA suit. In January 2013, U.S. District Court Judge Colleen McMahon ruled that she had no authority to order the documents disclosed, although she chided the White House for refusing to release them.

But a three-judge appeals court panel later rejected the government’s claim that the court could not consider official disclosures made after McMahon’s ruling, including a 16-page Justice Department white paper on the subject and public comments by Obama in May in which he acknowledged his role in the al-Awlaki killing.

The ACLU urged senators Tuesday not to move forward on the confirmation vote until they have a chance to see any Barron memos on the administration’s drone program, not just those involving U.S. citizens.

Paul issued a statement Tuesday saying he still opposes Barron’s nomination.