The former NSA contractor is wanted in the United States on a number of charges, including espionage and theft of government property. If convicted he faces up to 30 years in prison.
"In the United States, under the current law right now, it's not even possible for me to enjoy a fair trial," Snowden said during a conference held in Hanover, Germany, which was organized by the international computer expo CeBIT.
"I want to tell the jury why I did it, I want to tell the court what these programs are, I want the jury to decide whether it was right or wrong…but the law forbids it," he said.
In August 2013, Snowden was granted asylum and subsequently a three-year residency permit by Russia.
Since 2013, Snowden has been publishing information about the NSA's and other intelligence agencies' surveillance programs which allow them to filter millions of private messages from around the world. Snowden also indicated that among the communications tapped by NSA were the cell phones of dozens of world leaders, including German Chancellor Angela Merkel.