WASHINGTON (Reuters) -- The U.S. government has decided to disclose its legal justification for the use of drones against U.S. citizens suspected of terrorism, a senior Obama administration official said Tuesday.

The solicitor general has made the decision not to appeal a federal appeals court's decision in April requiring the release of the redacted memorandum spelling out the justification for the policy, the official said. The court and the Justice Department have not set a time for the document's release.

While the legal analysis that justifies the use of drones will be disclosed, some facts will still be excluded from the document, the official said.

In a case pitting executive power against the public's right to know what its government does, the 2nd U.S. Circuit Court of Appeals last month reversed a lower-court ruling preserving the secrecy of the legal rationale for the killings, such as the assassination of U.S. citizen Anwar al-Awlaki in a 2011 drone strike in Yemen.

Ruling for the New York Times in the case, a unanimous three-judge panel said the government waived its right to secrecy by making repeated public statements justifying targeted killings.

Civil liberties groups have warned that the drone program, which deploys pilotless aircraft, lets the government kill Americans without constitutionally required due process.

The U.S. use of drones against militants in countries like Pakistan and Yemen has drawn international criticism and has fanned anti-American sentiments in some Islamic countries.

(Reporting by Julia Edwards; Editing by Peter Cooney)