The U.S. charged Edward Snowden, the former defense contractor with espionage, for leaking sensitive information about the National Security Agency, or NSA, surveillance programs, a court document made public on Friday stated.

Snowden is charged with theft of government property, "unauthorized communication of national defense information" and "willful communication of classified communications intelligence information to an unauthorized person," in the federal criminal complaint cited by Reuters.

The complaint was filed on June 14 in Alexandria, Virginia, and a single-page of the document was unsealed on Friday.

Snowden, who admitted to leaking documents related to a NSA’s secret surveillance programs to media outlets, is believed to be hiding in Hong Kong, the island territory of China. Hong Kong though a part of China is governed by separate laws and judiciary.   

Apparently, the U.S. authorities are in regular talks with their Hong Kong counterpart seeking extradition of Snowden to the U.S. The criminal complaint filed against Snowden is the first step toward a long legal battle to initiate his arrest and extradition to the U.S., Bloomberg News reported quoting people familiar with the matter. 

The U.S. and Hong Kong share an “active extradition relationship” a law enforcement official told Reuters.

“They’re going to fight the extradition in Hong Kong,” Mark Zaid, a national security lawyer in Washington, was quoted as saying by Bloomberg News. “That could take months.”

However, Hong Kong is yet to respond to the issue officially, but some legislatures on Saturday said the decision on extradition of Snowden to the U.S. will be taken by the Chinese government, Associated Press reported.

So far, China has refused to comment on the presence of Snowden in Hong Kong.

Although, Hong Kong which became part of China in 1997 has a greater degree of autonomy, based on its constitution China can intervene on defense and diplomatic affairs.

Snowden, a former employee of Booz Allen Hamilton, admitted to leaking secret documents about NSA’s PRISM program earlier this month and is hiding since then. He acquired the classified documents relating to NSA’s surveillance program while working in a NSA facility at Hawaii as a systems analyst.  

He is hailed as a whistleblower by his supporters, who claim that his actions have exposed the illegal U.S. surveillance and breach of users’ right to privacy, while he is being regarded as a traitor and criminal by the U.S. administration for revealing sensitive information regarding the nation’s security.

Some of the charges filed against the 30-year-old systems analyst fall under the 1917 Espionage Act, which carry a maximum punishment of 10 years in prison, separately for each espionage charge pressed against him and fines.