Austria Summons U.S. Ambassador over Spy Scandal

Austria has summoned the U.S. ambassador to explain reports that Washington had bugged European offices and embassies amid a growing diplomatic row, a spokesman for Foreign Minister Michael Spindelegger said Monday.

The ambassador, William Eacho, will be called in on Tuesday to outline the U.S. position in the spiraling espionage scandal that has threatened to damage transatlantic ties.

"These accusations are unacceptable. We want an urgent explanation from the American side as to whether they are true and what espionage activities took place in Austria," Spindelegger told the Oesterreich local daily.

Over the weekend, German newsweekly Der Spiegel reported that the U.S. National Security Agency (NSA) carried out covert surveillance on EU diplomatic missions.

Spiegel said its report was partly based on confidential documents it had been able to consult via fugitive U.S. leaker Edward Snowden.

European sources said anger over the scandal was genuine and warned it could escalate into a "serious" political crisis, just as the EU and U.S. are to begin tricky talks on a free trade deal which would be the biggest ever negotiated.

In neighboring Germany, Europe's political and economic heavyweight, a foreign ministry spokesman said the U.S. ambassador had been "invited" to discuss the issue.

He stressed however that the envoy had not been "summoned" -- a formal diplomatic move when tensions develop between governments.