The journalist who exposed classified U.S. surveillance programs leaked by a former American defense contractor says there will be more "significant revelations" to come.
Glenn Greenwald of Britain's newspaper "The Guardian" told the Associated Press that "there are dozens of stories" that will be generated by documents provided by Edward Snowden, who once worked for the U.S. National Security Agency and the CIA. He said on June 11 that a decision was being made on when to release the next story.
Greenwald wrote the reports last week which revealed large-scale U.S. government programs to collect telephone and Internet records.
One program collects hundreds of millions of U.S. phone records to search for possible links to known terrorist targets abroad. The second program with the code name "Prism" allegedly allows the government to collect data from e-mails and other Internet activities from major U.S.-based Internet providers, social networks, and technology companies.
It is not clear how much Internet-based information the U.S. government is seizing or accessing, but President Barack Obama has described the second program as "very narrowly circumscribed" and "very focused."
Some of the companies accused of participating in the program such as Facebook, Apple, Microsoft, and Google deny they have allowed the government "direct access" to their servers.
Snowden was fired on June 11 by Booz Allen Hamilton, the private U.S. firm that works under U.S. government contracts. The company said that Snowden has been dismissed for "violations of the firm's ethic codes and firm policy."
Snowden has said he leaked the information to protect the basic privacy of people around the world. The 29-year-old was identified as the source of the leaks at his own request on June 9.
White House spokesman Jay Carney defended the programs on June 10.
"It's entirely appropriate for a program to exist to look at foreign data and potential foreign terrorists," he said. "But there are procedures in place as the [National Security Agency] Director [Keith Alexander] made clear, as the president made clear -- both at the congressional, executive and judicial levels -- that provide oversight."
WATCH: Assange says he's had indirect contact with Snowden
Carney maintained that President Obama has carefully considered the impact of the programs on privacy issues.
"We need to strike the appropriate balance between our national security and our interests in privacy," he said. "The fact that, coming into office, [U.S. President Barack Obama] assessed, and his team assessed, programs that existed and in some cases enhanced oversight, and he believes with the oversight that exists and the implementation of the programs as they are implemented that the balance is appropriately struck, has been appropriately struck, but it is an absolutely appropriate topic for debate."
Snowden's exact location is unknown. He is reported to have checked out of a Hong Kong hotel on June 10.
Some U.S. lawmakers have demanded that Snowden be sent back to the United States to face charges.
The Justice Department has said it is investigating whether his disclosures were a criminal offense.
A petition to pardon Snowden posted on the White House website had attracted more than 40,000 electronic signatures by the morning of June 10.
In Moscow, Dmitry Peskov, the spokesman for Russian President Vladimir Putin told the "Kommersant" newspaper that Russia would consider an asylum request from Snowden, if it were made.
With reporting by AP, Reuters, AFP, and kommersant.ru