The largest US spy agency has acknowledged that it intercepted private communications of some 35 world leaders.
Officials say an internal review revealed the existence of the international spying operation in the National Security Agency, the Wall Street Journal reports.
It is the first public acknowledgment of intercepting telephone communication of world leaders by the US Government.
European politicians have expressed outrage over revelations of US surveillance on German Chancellor Angela Merkel’s private mobile telephone and mining of data in France.
The Spanish government summoned the US ambassador on Monday to respond to allegations that the NSA intercepted more than 60 million calls in Spain.
The calls were intercepted in December and January, according to documents leaked by former NSA contractor, Edward Snowden, Guardian journalist Glenn Greenwald wrote in El Mundo newspaper.