An Italian judge has set a February date for the trial of two US teenagers charged with killing a police officer during a botched drug deal in Rome.

The killing of Mario Cerciello Rega, who was in plain clothes when he was stabbed to death on July 26, sparked a national outcry.

On Thursday, Judge Chiara Gallo set a February 26 trial date in the case against Finnegan Elder, 19, and Gabriel Natale Hjorth, 18, who are being held in a Rome jail.

Both are facing charges of voluntary manslaughter and attempted extortion, according to Italian media reports.

Officer Mario Rega Cerciello's death sparked a national outcry
Officer Mario Rega Cerciello's death sparked a national outcry AFP / Eliano IMPERATO

Police have said that Elder confessed to stabbing Cerciello Rega, 35, with a combat knife.

Cerciello Rega and his partner intercepted the teens after an intermediary on a drug deal reported them to the police for stealing his bag after they were sold aspirin instead of cocaine.

Police tracked the teens to their four-star hotel after the attack, where they found a large knife hidden in the false ceiling of their room.

Many questions remain about the events of the night, but on Tuesday La Repubblica newspaper published leaked, intercepted statements from Elder in prison saying the teens knew that Cerciello Rega and his partner, Andrea Varriale, were police as they identified themselves as such.