BERLIN -- European leaders reacted with fury Sunday to allegations in a German magazine that the United States had conducted a wide-ranging effort to monitor European Union diplomatic offices and computer networks, with some saying that they expected such surveillance from enemies, not their closest economic partner.
It was the latest fallout from National Security Agency information apparently leaked by Edward Snowden, a former NSA contractor whose detailing of classified information on the agency's programs has shined a rare light on U.S. surveillance efforts that range far wider than previously understood.
The United States has been trying to track down Mr. Snowden, who fled from Hawaii to Hong Kong and is thought to be in the transit area of Moscow's Sheremetyevo International Airport. He had apparently been trying to reach Ecuador, but comments Sunday from Ecuadoran President Rafael Correa made it sound as though the country may be cautious about accepting him.
Also, Julian Assange, the founder of the anti-secrecy organization WikiLeaks, said Sunday that disclosures from the classified documents Mr. Snowden took would continue.
"Look, there is no stopping the publishing process at this stage," Mr. Assange said on the ABC News program "This Week." "Great care has been taken to make sure that Snowden can't be pressured by any state to stop the publication process."
WikiLeaks played no role in Mr. Snowden's disclosures, but since joining forces with him, the organization has used his case to raise its own profile again. Mr. Assange spoke from the Ecuadorean Embassy in London where he has been ensconced for more than a year after being granted asylum.
Underscoring the depth of the European anger over the NSA spying allegations, top officials from several European countries said the reports would figure into the future of trans-Atlantic trade talks that began in June. The efforts would create the world's largest free trade zone, and European officials said Sunday that they suspected the target of U.S. intelligence interest was economic information, not military.
"Partners do not spy on each other," said European Commissioner for Justice Viviane Reding on Sunday at a public event in Luxembourg. "We cannot negotiate over a big trans-Atlantic market if there is the slightest doubt that our partners are carrying out spying activities on the offices of our negotiators."
Other European leaders said they felt blindsided by the allegations.
"It is shocking that the United States take measures against their most important, their nearest allies, comparable to measures taken in the past by the KGB, by the secret service of the Soviet Union," European Parliament President Martin Schulz told reporters Sunday in Brussels.
"This is not the basis to build mutual trust, this is a contribution to build mutual mistrust," he said, adding that he felt treated like an "enemy."
Germany's Der Spiegel newsmagazine reported this weekend that the NSA had placed listening devices in EU diplomatic offices in Washington and New York City, had breached an EU computer network that provided access to internal emails and documents, and had accessed phone lines in EU headquarters in Brussels in order to monitor top officials' phone conversations. The magazine said it had seen portions of 2010 documents from Mr. Snowden, although it did not publish them on its website nor did it quote from them directly.
Later on Sunday, Britain's Guardian newspaper published additional information, including portions of an internal NSA presentation that appear to detail several methods by which U.S. intelligence agencies monitored diplomats inside the United States. The "Dropmire" program apparently monitored communications on an encrypted fax machine used by the EU delegation in Washington to communicate with counterparts in Europe.
The Guardian also reported that another document lists 38 embassies and missions that U.S. intelligence agencies were monitoring in some way, including the embassies of U.S. allies France, Italy, Japan, India and South Korea, and others including more traditional antagonists and Middle Eastern countries.
EU foreign policy chief Catherine Ashton said in a statement Sunday that she had asked for further information from U.S. officials in Washington and Brussels.
A spokesman from the Office of the Director of National Intelligence said Sunday that the U.S. government would respond through diplomatic channels.
Der Spiegel on Sunday separately reported that the NSA monitored 500 million emails, phone calls and text messages in Germany every month, more than any European peer. Germany's Federal Prosecutor's office said Sunday that it would open an inquiry to determine whether charges should be filed.
The revelations of U.S. spying have special resonance in Germany, where memories of omnipresent Stasi surveillance in East Germany remain fresh. German Chancellor Angela Merkel was one of the first leaders to demand more information from President Barack Obama when revelations of U.S. surveillance were first disclosed earlier in June.
Ms. Merkel did not immediately respond this weekend to the new allegations, although she said ahead of a visit by Mr. Obama two weeks ago that U.S. intelligence had previously helped foil terrorist attacks in Germany.
New York Times contributed.