BERLIN — Edward J. Snowden, the fugitive American security contractor granted temporary asylum by Russia, has appealed to Washington to stop treating him like a traitor for revealing that the United States has been eavesdropping on its allies, a German politician who met with Mr. Snowden said on Friday.

Mr. Snowden made his appeal in a letter that was carried to Berlin by Hans-Christian Ströbele, a veteran member of the Green Party in the German Parliament. Mr. Ströbele said he and two journalists for German news outlets met with Mr. Snowden and a person described as his assistant — probably his British aide, Sarah Harrison — at an undisclosed location in or near Moscow on Thursday for almost three hours.

Mr. Ströbele had gone to Moscow to explore whether Mr. Snowden could or would testify before a planned parliamentary inquiry into the eavesdropping. Any arrangements for Mr. Snowden to testify would require significant legal maneuvering, as it seemed unlikely that he would travel to Germany for fear of extradition to the United States.

In his letter, Mr. Snowden, 30, also appealed for clemency. He said his disclosures about American intelligence activity at home and abroad, which he called “systematic violations of law by my government that created a moral duty to act,” have had positive effects.