German Chancellor Angela Merkel is among the European leaders concerned about U.S. intelligence service surveillance. (TOBIAS SCHWARZ/REUTERS)

European leaders, describing themselves as stunned by revelations of an extensive U.S. surveillance program that included their citizens, moved Monday to demand more information from the U.S. government and said they would discuss ways to bolster their already stringent privacy laws.

And in Britain, where intelligence agencies have long had robust cooperation with their American counterparts, a top official tried Monday to limit potential uproar, telling Parliament that the partnership had not been used to circumvent British laws.

The discontent from Europe pointed to the breadth of fallout from the affair and to the potential for fresh strains between the United States and allies wary of American intrusiveness.

German Chancellor Angela Merkel vowed to raise the issue when she meets in Berlin with President Obama next week, a spokesman said, and other German officials said they were concerned by the apparent monitoring of their citizens. Top officials of the 27-nation European Union also said they would press the U.S. government on the matter at bilateral meetings this week.

The PRISM surveillance program, portions of which were described in recent days by The Washington Post and the Guardian newspaper in Britain, makes clear that U.S. intelligence services now have the power to vacuum up data about telecommunications traffic across the world. An apparent snapshot from an NSA Boundless Informant database published on the Guardian’s Web site indicated that in March 2013, foreign intelligence gathering was primarily focused on the Middle East. For that month, more pieces of intelligence were gathered in Germany than anywhere else in Europe.

In Germany, where memories of East German Stasi surveillance remain fresh, privacy has powerful defenders. Individual German states have pursued cases against Facebook and Google in recent years, complaining that the companies did not do enough to give users power over their own information. The breadth and ambitions of the U.S. intelligence program far exceed any issues raised previously with private firms.

Merkel to meet Obama

When Merkel meets Obama, “you can safely assume that this is an issue that the chancellor will bring up,” Merkel’s spokesman, Steffen Seibert, told reporters on Monday. Merkel grew up in the East German system, where the government collected vast amounts of information about its citizens.

Other German officials said they were unhappy that their citizens appeared to have fewer rights than Americans.

“I cannot be happy that U.S. citizens might be protected in an appropriate way — I’m not sure if they are — but we are not,” said German Federal Data Protection Commissioner Peter Schaar, who is charged with protecting the privacy of German citizens both from private companies and from governments. “In the Internet, we cannot distinguish anymore between us and them, inside and outside our country. It’s an international network, and the data is going around the world.”

He said that German users of American-run services such as Facebook and Gmail needed to understand that U.S. authorities had “broad access” to their data.

One analyst said the concerns are not merely about privacy, but also economic.

“The German business community is on high alert,” said Volker Perthes, director of the German Institute for International and Security Affairs. “It’s not just about listening in on some bearded guy from Ulm who bought a ticket to Afghanistan and makes conversation with his friends in Waziristan. . . . The suspicion in large parts of the business sector is that Americans would also be interested in our patent applications.”

Asked Monday about the concerns raised by Merkel and other foreign leaders, White House press secretary Jay Carney said that Obama “believes that this is a conversation especially worth having and a debate especially worth having here in the United States, but obviously beyond, as well. He believes when it comes to Section 702, which the director of national intelligence has discussed in some detail, that it’s entirely appropriate for a program to exist to look at, you know, foreign data and potential foreign terrorists.”

Carney was referring to Section 702 of the Foreign Intelligence Surveillance Act, which requires the government to seek approval from a secret national security court to obtain the records of private citizens from communications companies.

Reaction in Britain

In Britain, which cooperates extensively with American intelligence agencies, Foreign Secretary William Hague appeared in the House of Commons to defend his government’s handling of information that may have been legally obtained under U.S. law but illegally under British law.

“Any data obtained by us from the United States involving U.K. nationals is subject to proper U.K. statutory controls and safeguards,” he said.

Viviane Reding, a European Commission vice president, will raise issues related to the NSA surveillance program in Thursday meetings with U.S. officials, a spokeswoman said.

“A clear legal framework for the protection of personal data is not a luxury or constraint but a fundamental right,” Reding said in a statement.

Elsewhere, reaction to the revelations about American surveillance operations was mixed. In Russia — whose intelligence agencies conduct domestic surveillance of their own — there was little immediate reaction. In India, commentators complained that the U.S. government had recently rebuffed Indian attempts to access the data of companies such as Facebook and Google to fight crime.

Kathy Lally in Moscow, Rama Lakshmi in New Delhi and Scott Wilson in Washington contributed to this report.