The CIA is alleged to have flown terror suspects from Europe to states that practice torture.
An Italian court has ordered 26 Americans and six Italians to stand trial in connection with the CIA's "extraordinary rendition" program.
The 35 are scheduled to go to trial June 8 for allegedly kidnapping and transferring a terror suspect to third countries. Three other Italians face charges of complicity in the kidnappings.
However, none of the Americans -- almost all CIA agents -- is in custody in Italy and the Italian government has not asked for their extradition to Italy.
The case revolves around the alleged kidnapping of Osama Nasr Mostafa Hassan, an Egyptian-born Muslim cleric, also known as Abu Omar, in February 2003.
At the time of his disappearance, Milan prosecutors were investigating him for alleged links to terrorism.
Prosecutors allege that a CIA team working with Italian intelligence officials seized him, eventually flying him to Egypt, and used torture as part of an interrogation there.
In an earlier interview, former CIA analyst Michael Scheuer said the Italian military secret service had approved the operation, and CIA sources who refused to be named told CNN in 2005 that the agency had briefed and sought approval from its Italian counterpart for such an abduction.
But the Italian government of former Prime Minister Silvio Berlusconi has vigorously denied having authorized Hassan's kidnapping, which it called illegal.
Human rights groups condemn the practice known as "extraordinary rendition," saying suspects have often been sent by the U.S. to countries that practice torture.
Washington acknowledges making secret "rendition" transfers of terror suspects between countries, but denies using torture itself or handing suspects over to countries that do so.