The White House on Thursday refused to comment on whether US spy agencies had monitored German Chancellor Angela Merkel's mobile phone in the past, dpa reported.
Spokesman Jay Carney said he would "not comment publicly on every specified alleged intelligence activity" after saying a day earlier that the United States was not currently monitoring Merkel's calls and would not do so in the future.
He acknowledged the National Security Agency scandal had damaged relations with key allies, saying it had "clearly caused some tensions with our relationships."