Germany yesterday expelled the US secret services station chief in Berlin in an escalating row over alleged American spying against its long-time European ally.
The worst diplomatic rift in years comes after two suspected US spy cases were uncovered in less than a week in Germany, where anger still simmers over the NSA surveillance scandal sparked by fugitive intelligence contractor Edward Snowden.
"The representative of the US intelligence services at the embassy of the United States of America has been told to leave Germany," government spokesman Steffen Seibert said.
The demand was based on two probes by German prosecutors of suspected US spying "as well as outstanding questions over the last several months about the activities of the US secret services in Germany".
"The government takes these developments very seriously," Seibert added.
The White House refused to comment, but the US embassy in Berlin and the National Security Council both said it was "essential" that cooperation continued on security matters as "it keeps Germans and Americans safe".
German Chancellor Angela Merkel - whose mobile phone was in the past targeted by the US National Security Agency (NSA) - pointedly reminded the US that security "depends on trust" between allies.
Finance Minister Wolfgang Schaeuble was far more outspoken, saying of the suspected US spying that "so much stupidity just makes you want to cry". In the latest case, German police on Wednesday searched the Berlin-area home and office of a man who, local media reported, is a German defence ministry employee accused of passing secrets to the US.
The case followed news last Friday that a 31-year-old German BND foreign intelligence service operative had been arrested on suspicion of selling more than 200 documents to the CIA.
The documents provided by the BND mole reportedly included papers on a German parliamentary panel that is probing the NSA's mass surveillance activities and the extent of German cooperation in the snooping.
The five ring binders, the contents of which were transferred digitally via a USB stick, were thought to contain instructions from Merkel's office to the head of the BND and an overview of the agency's network of overseas posts, the Die Welt daily reported. While German politicians across party lines have deplored the covert activities as a betrayal of trust by Washington, the German foreign ministry has twice discussed the case with the US ambassador in Berlin in recent days.
Interior Minister Thomas de Maiziere dismissed the damage done in the latest reported spy cases, saying that "based on what we know now, the information gained through this alleged espionage is ridiculous".
Schaeuble, a former interior minister, acknowledged transatlantic intelligence cooperation had foiled terrorist threats in the past.
But he said this did not mean "the Americans may recruit third-rate people" in Germany as their secret sources.
Merkel later said that "common sense tells us that spying on one's allies ... is a waste of energy".
The chancellor said she saw "a very different approach" on both sides of the Atlantic "as to what the job of intelligence services is ... after the end of the cold war".
Mentioning common threats for the allies, she said: "I think that in these times, which can be very confusing, very much depends on trust between allies ... More trust can mean more security".