The U.S. expressed "disappointment" over the kidnapping convictions of 23 Americans, Reuters reported.
"We are disappointed by the verdicts against the Americans and Italians charged in Milan for their alleged involvement in the case involving Egyptian cleric Abu Omar," State Department spokesman Ian Kelly said, according to Reuters.
"The judge has not yet issued a written opinion so we're not in a position to comment further on the decision."
The American Civil Liberties Union called on the U.S. to hold the Americans involved in the illegal rendition and torture of detainees accountable for their actions.
"The decision in Italy underscores the need for the United States to hold its own officials accountable for crimes committed under the 'extraordinary rendition' program," said Steven Watt, staff attorney for the ACLU Human Rights Program.
"It is shameful that the first convictions of this kind came from a foreign justice system, where those convicted are not likely to serve their time."
An Italian judge on Wednesday convicted 23 Americans in absentia of the 2003 kidnapping of an Egyptian cleric from a Milan street, in a landmark case involving the CIA's extraordinary rendition program in the war on terrorism.
Citing diplomatic immunity, Judge Oscar Magi told the Milan courtroom Wednesday that he was acquitting three other Americans.
Former Milan CIA station chief, Robert Seldon Lady, received eight years in prison. The other 22 convicted American defendants each received a five-year sentence.
The Americans, all but one identified by prosecutors as CIA agents, were tried in absentia as subsequent Italian governments refused or ignored prosecutors' extradition request.
In Washington, CIA spokesman George Little declined to comment on the convictions. He said, "The CIA has not commented on any of the allegations surrounding Abu Omar," the kidnapped man.
Lawyers for the 23 convicted Americans said they would appeal the convictions. The Americans remain fugitives from Italian justice and prosecutor Armando Spataro said he was considering asking the government to issue an international arrest warrant on the strength of the conviction. The government of Silvio Berlusconi, a close ally of President George W. Bush, has previously refused.
Magi said he was acquitting five Italian defendants because an Italian high court ruled key evidence inadmissible as classified. Two of the Italian defendants were convicted as accomplices to kidnapping and received three-year sentences.
The verdict "sends a strong signal of the crimes committed by the CIA in Europe," said Joanne Mariner of Human Rights Watch. The crimes were "unacceptable and unjustified," said Mariner, who was in the courtroom for the verdict at the end of the nearly 3-year-long trial.
The Americans were accused of kidnapping Osama Moustafa Hassan Nasr, also known as Abu Omar, on Feb. 17, 2003, in Milan, then transferring him to U.S. bases in Italy and Germany. He was then moved to Egypt, where he says he was tortured. He has since been released, but has not been permitted to leave Egypt to attend the trial.
The trial is the first by any government over the CIA's extraordinary rendition program, which transferred suspects overseas for interrogation. Human rights advocates charge that renditions were the CIA's way to outsource the torture of prisoners to countries where it is permitted.
The Milan proceedings have been a sore spot in relations between the United States and Italy. The CIA has declined to comment on the case, and Italy's government has denied involvement.
Among the Americans acquitted was Jeffrey Castelli, a former Rome CIA station chief, who prosecutors had alleged coordinated the abduction. The two other acquitted Americans were also assigned to the U.S. Embassy in the Italian capital and thus were covered by broad diplomatic immunity.
The trial continued despite obstacles that threatened to derail it, including Rome's refusal to cooperate with prosecutors.
In addition, Italy's highest court ruled some key evidence inadmissible because it is considered classified — including dossiers seized from the Rome apartment of an Italian intelligence agent and the testimony of a carabinieri officer allegedly at the scene of the kidnapping. That ruling was cited in the acquittal of the main Italian defendants, including the former head of military intelligence.
The government's will to enforce the verdict against the Americans, however, is unlikely to be tested any time soon. Sentences in Italy aren't served until all appeals are exhausted, a process that can take years.
The court also ruled that those convicted must pay 1 million euros to the Egyptian in damages and 500,000 euros to his wife.
The Associated Press contributed to this report.