German Chancellor Angela Merkel has reportedly phoned US President Barack Obama Wednesday, over allegations US spy agencies monitored her telephone conversations.
The Chancellor's spokesman released a statement saying that Merkel "views such practices... as completely unacceptable."
"Among close friends and partners, as the Federal Republic of Germany and the US have been for decades, there should be no such monitoring of the communications of a head of government," the statement continued.
The revelations comes amid a swirl of controversy over US spy agencies' intelligence gathering techniques, in the wake of the Snowden Leaks scandal.
But White House spokesperson Jay Carney denied that intelligence agencies had snooped on the German leader's private calls, insisting that "The United States is not monitoring and will not monitor the communications of the chancellor."
Carney did, however, confirm that the Obama administration was reviewing intelligence practices after a string of complaints by key US allies, including France.
Just a day earlier, France's Le Monde newspaper published allegations that US spies recorded data from 70 million phone calls in France in a single 30-day period - a claim strenuously denied by US Director of National Intelligence, James Clapper.
"The allegation that the National Security Agency collected more than 70 million 'recordings of French citizens' telephone data' is false," said Clapper, in a statement to the media. Clapper added he would not discuss details of surveillance activities, but acknowledged "the United States gathers intelligence of the type gathered by all nations".
He did not, however, address a second allegation that US National Security Agency (NSA) programs bugged French diplomats in Washington and at the UN and used the information to sway a key UN vote on a resolution imposing new sanctions on Iran on June 9, 2010.
The US had apparently feared losing the vote, and needed French support. A leaked NSA document quotes America's former UN envoy Susan Rice as saying the NSA's information helped the US "keep one step ahead in the negotiations".