It is the second time, however, the free-trade talks have hung in the balance because of French concerns. Two weeks ago, as the EU was deciding on its mandate for the talks, France led an all-out campaign to keep cultural industries off the table that almost scuttled the negotiations.
The European Commission also demanded an explanation. Their foreign affairs chief spoke to Kerry on Monday about the reports at a security conference in Southeast Asia.
"I will say that every country in the world that is engaged in international affairs with national security undertakes lots of activities to protect its national security and all kinds of information contributes to that," Kerry said on the sidelines in Brunei, adding that he had been busy with meetings about the Mideast peace process and wasn't familiar with the specifics of the most recent claims.
"And all I know is that that is not unusual for lots of nations. But beyond that, I'm not going to comment any further until I have all the facts and find out precisely what the situation is," he said.
It's unclear how widespread similar practices actually are. But some in Europe have raised concerns that U.S. efforts include economic espionage. When asked whether Germany spies on its allies, Seibert responded: "It's not the policy of the German government to eavesdrop on friendly states in their embassies. That should be obvious."
Italy also stepped up its criticism of the surveillance on Monday, with Foreign Minister Emma Bonino saying Italy had asked the Americans for the "necessary clarifications for this very thorny issue." In a statement, Bonino said the Americans had promised to provide clarification to both the EU and individual member states.
Italy has largely downplayed earlier reports of Snowden's revelations, even that the U.S. had spied on G-20 members, in part because Italians are so used to being listened in on by their own government. Italy is the most wiretapped Western democracy, with transcripts of telephone intercepts of politicians and criminals routinely splashed on front pages.