CINCINNATI — The Bush administration may proceed with its warrantless surveillance program while it appeals a judge’s ruling that the program is unconstitutional, a federal appeals court ruled yesterday.

The president has said the program is needed for America’s war on terrorism; opponents argue that it oversteps constitutional boundaries on free speech, privacy, and executive powers.

The unanimous ruling from a three-judge panel of the 6th U.S. Circuit Court of Appeals gave little explanation for the decision. In the three-paragraph ruling, judges said they balanced the likelihood an appeal would succeed, the potential damage to both sides, and the public interest. U.S. District Judge Anna Diggs Taylor in Detroit ruled August 17 that the program was unconstitutional because it violates the rights to free speech and privacy and the separation of powers in the Constitution. The Justice Department had urged the appeals court to allow it to keep the program in place while it argues its appeal, claiming that the nation faced “potential irreparable harm.” The appeal is likely to take months.

The program monitors international phone calls and e-mails to or from America involving people the government suspects have terrorist links. A secret court has been set up to grant warrants for such surveillance, but the government says it can’t wait for a court to take action.

The American Civil Liberties Union filed a lawsuit seeking to stop the program on behalf of journalists, scholars, and lawyers who say it has made it difficult for them to do their jobs because they believe many of their overseas contacts are likely targets. Many said they had been forced to take overseas trips because their contacts wouldn’t speak openly on the phone or didn’t want to violate their contacts’ confidentiality.