Kristian Saucier, of Arlington, Vermont, is scheduled to be sentenced Friday in federal court in Bridgeport.

Saucier pleaded guilty in May to unauthorised detention of defence information.

He faces five to six years in prison under sentencing guidelines, but is asking for probation.

Saucier compares his case to Democratic presidential nominee Hillary Clinton's use of a private email server when she was secretary of state. The FBI declined to charge Clinton for her handling of classified information while using the server.

Saucier took six photos with his cellphone inside the USS Alexandria in 2009 when it was in Groton.

Prosecutors are seeking a five-year prison sentence.