ATHENS — Edward J. Snowden, the former American intelligence contractor who leaked documents about surveillance programs, said on Friday that his disclosures had improved privacy for individuals in the United States, and he declared that “being patriotic doesn’t mean simply agreeing with your government.”

Mr. Snowden also said he was grateful for a campaign, led by human rights and civil liberties groups, calling on President Obama to pardon him, a move that would allow him to return to the United States without facing the prospect of many years in prison.

In 2013, after The Guardian and The Washington Post published articles about widespread, secret National Security Agency surveillance and data collection programs, Mr. Snowden identified himself as the source of the information. He had fled to Hong Kong, with the aim of escaping to Latin America via Moscow, but his passport was annulled and he was left stranded in at a Moscow airport.

If he is not pardoned, he could face charges on two counts under the 1917 Espionage Act, which does not allow for a “public interest” or “whistle-blower” defense, making it almost impossible for him to explain his motivations or present a proper defense, Mr. Snowden said.