A new document by American whistleblower Edward Snowden reveals that the United States has monitored the telephone conversations of 35 world leaders.
The Guardian reported on Thursday that officials from the White House, the US Department of Defense, and the State Department gave the world leaders’ numbers to the National Security Agency.
One unnamed American official handed over 200 numbers, including those of the 35 world leaders, none of whom is named, according to the document.
"A US official provided NSA with 200 phone numbers to 35 world leaders … Despite the fact that the majority is probably available via open source, the PCs [intelligence production centers] have noted 43 previously unknown phone numbers. These numbers plus several others have been tasked," the confidential memo said.
"These numbers have provided lead information to other numbers that have subsequently been tasked," it added.
The new revelation came just one day after German chancellor Angela Merkel announced that Washington is tapping her mobile phone.
"We need trust, and now the trust has to be reestablished," Merkel said. "Spying among friends is never acceptable.”
"Now we have to discuss what sort of data protection do we need and what sort transparency is there," she said.
However, the White House said in a statement that the US "is not monitoring and will not monitor" the German chancellor's communications.
During a press conference on Thursday, White House spokesman Jay Carney acknowledged Washington's suffering from the NSA revelations.
"The revelations have clearly caused tension in our relationships with some countries, and we are dealing with that through diplomatic channels,” Carney said.
"These are very important relations both economically and for our security, and we will work to maintain the closest possible ties," he added.
The documents released over the past few months reveal a troubling picture of a super spy agency that has sought and won far-reaching surveillance powers to run complex domestic data collection without anyone having full technical understanding of the process.
The privacy violations were first revealed by Snowden in June. He leaked confidential information that showed the NSA collects data of phone records and Internet communication of American citizens.
The former NSA contractor, who is charged with espionage in the United States, fled the US and took one-year asylum from Russia in August. Snowden supplied reporters with 50,000 secret documents.