Edward Snowden, ex-contractor of the National Security Agency (NSA) who has been in the news lately for disclosure of multiple documents about a secret program by United States, will be shown no mercy, said senior US lawmakers on Sunday, according to BBC.

Dan Pfeiffer, a White House adviser said, "Mr. Snowden violated US law. He should return to the US and face justice."

Snowden requested in a letter to a German politician that international help may be sought in order to convince the United States to remove spying charges against him.

Snowden, 30, left Hong Kong to seek asylum in Russia in the month of June after disclosing the secret surveillance program run by US government. He was given temporary asylum in Russia lasting July 2014.

Last week a meeting took place between German Green MP and Snowden in Moscow. The agenda for the meeting was how NSA was spying on the German government.

Hans-Christian Stroebele showed the letter to reporters during a news conference held in Berlin on Friday.

"Speaking the truth is not a crime. We would have seen him and we would have looked at that information. That didn't happen, and now he's done this enormous disservice to our country," said US Senator Dianne Feinstein about Snowden’s leaking of secret information of the US government. "I think the answer is no clemency,” she added.