President Obama defended U.S. intelligence-gathering tactics Monday in the wake of a report that the United States conducted electronic monitoring of European Union offices and computer networks.

In Asia, Secretary of State John F. Kerry said he was taken by surprise when E.U. foreign policy chief Catherine Ashton questioned him about the reported eavesdropping.

The German magazine Der Spiegel said Sunday that the conduct was described in portions of documents from 2010 provided by Edward Snowden, the former U.S. National Security Agency contractor whose earlier revelations about international NSA surveillance have caused a firestorm of questions and criticism in the United States. The report said the agency had placed listening devices in E.U. offices in Washington and New York, monitored phone lines at the E.U.’s Brussels headquarters and breached its computer network.

Der Spiegel said the NSA described the 27-country bloc a “target.” The report has prompted outrage from top European officials.

At a news conference here Monday during his African tour, Obama said he has asked aides to look more closely at the revelations in the story, and he declined to comment on the specifics. But more generally, the president said all spy agencies gather information beyond that which is publicly available from large media organizations such as the New York Times and NBC News.

“They are seeking additional insight beyond what’s available through open sources,” he said. “And if that weren’t the case, then there would be no use for an intelligence service. And I guarantee you that in European capitals, there are people who are interested in, if not what I had for breakfast, at least what my talking points might be should I end up meeting with their leaders. That’s how intelligence services operate.”

The president insisted that there was nothing sinister about the NSA’s methods, emphasizing that any information he is given is less important than his personal conversations with European leaders.

“I’m the end user of this kind of intelligence, and if I want to know what [German] Chancellor [Angela] Merkel is thinking, I will call Chancellor Merkel,” he said.

The allegations made by Der Spiegel are the latest in a string of revelations on the tactics of the NSA , which also has been collecting massive amounts of Americans’ cellphone records and monitoring computer records of big Internet companies such as Facebook and Google. The disclosures, made by The Washington Post and the Guardian newspapers, as well as Der Spiegel, were facilitated by former Snowden, who has been charged by the U.S. government with several felonies related to the leaks.

Snowden has left the United States and is presumed to be in Russia. Obama declined to confirm a report that he and Russian President Vladimir Putin have asked their law enforcement agencies to negotiate a return of Snowden to the United States. The United States does not have an extradition treaty with Russia, potentially making a turnover more difficult.

Obama sought to reaffirm the alliance between the United States and the European Union.

“Ultimately, we work so closely together that there’s almost no information that’s not shared between our various countries,” he said.

In Bandar Seri Begawan, capital of the sultanate of Brunei, Kerry said Ashton, the E.U.’s top diplomat, surprised him by raising the issue.

“I honestly hadn’t heard about it. I hadn’t seen any of those reports,” said Kerry, who has spent the last several days immersed in shuttle diplomacy in the Middle East. He arrived in Brunei Monday morning, after an all-night flight from Israel, on the last stop of an eight-nation tour.

At a news conference, Kerry said Ashton “did indeed raise it with me” in a meeting of Asian foreign ministers that both are attending. He said he told Ashton he did not yet have “all the facts” and would get back to her.

European officials and politicians have reacted furiously, with some saying the revelations may harm efforts that began this month to negotiate a transatlantic free trade zone, a high foreign policy priority for the Obama administration.

“We cannot accept this type of behavior between partners and allies,” French President Francois Hollande said Monday, Le Figaro reported. “We ask that it stop immediately.”

European Commission President Jose Manuel Barroso has ordered a sweep of European Commission headquarters to search for monitoring devices, a spokeswoman said in Brussels on Monday.

And in Berlin, a spokesman for Merkel said she is “alienated” by the alleged eavesdropping. “We are no longer in the Cold War,” spokesman Steffen Siebert said. U.S. Ambassador to Germany Philip D. Murphy was summoned to the Foreign Ministry for consultations on the issue.

The allegations of surveillance have special resonance in Germany, where memories of East German Stasi spying are fresh and Nazi-era crimes also lurk in the back of people’s minds. With German parliamentary elections in less than three months, Merkel is under extra pressure to take a hard line against the United States on the issue.

Italian President Giorgio Napolitano said Monday that “it’s a thorny issue that needs to be met by satisfactory responses,” Italy’s ANSA news agency reported. And in France, Harlem Desir, the chairman of Hollande’s Socialist Party, said that the allegations, if confirmed, would “naturally” have an impact on trade negotiations with the United States.

In a statement released in Washington on Sunday, the Office of the Director of National Intelligence appeared to imply at least some truth to the report. “As a matter of policy,” the statement said, “we have made clear that the United States gathers foreign intelligence of the type gathered by all nations.”

After his apparent surprise at Ashton’s questions, Kerry seemed to have reviewed the DNI statement by the time of his news conference about two hours later.

“Every country in the world that is engaged in international affairs undertakes all kinds of activities to protect its national security. All I know is that it is not unusual,” Kerry said. “I want to see the allegations, number one. Then, number two, I need to find out what the truth of the situation is.”

Although he is physically distant from the uproar over Snowden’s leaks, the issue — and the question of how to capture Snowden, who has been charged with revealing government secrets but remains on the run — has dogged Kerry throughout his trip.

After initial stories on Snowden’s revelations appeared in The Washington Post and the Guardian last month, he surfaced in Hong Kong but was allowed to leave on a flight to Moscow despite U.S. requests and an arrest warrant. With his U.S. passport revoked, Snowden is now stuck in transit facilities at Moscow’s Sheremetyevo Airport, where Putin has said his government has no authority to detain him.

Kerry said he had briefly discussed Snowden in a meeting at the ASEAN conference with Chinese Foreign Minister Wang Yi.

“It’s safe to say that the United States of America, the Obama administration, believes that our friends in China could in fact have made a difference” in Snowden’s movements, Kerry said.

One German opposition politician suggested that Europe should give Snowden a home. “He should have an appropriate, secure accommodation here in Europe,” Green Party parliamentary head Juergen Trittin told German television on Monday. “Because he has done Europe a service by revealing a massive attack on European citizens and businesses.

The Snowden issue is also expected to come up on Tuesday, when Kerry meets here with Russian Foreign Minister Sergei Lavrov.

But Kerry made clear that he had other issues to discuss and tried at the news conference to steer reporters toward the Obama administration’s Asia agenda. Meetings here on Monday and Tuesday include a gathering of the 10-nation Association of Southeast Asian Nations, followed by an expanded Asian regional meeting that includes North Korea, and a preparatory ministerial meeting of the annual East Asia Summit, which President Obama will attend here in october.

With China, “we have a lot of issues that we’re dealing with right now. Issues of major maritime security . . . [and] major, major issues with respect to North Korea, [where] China is cooperating with us,” Kerry said.

“Life and international relationships are often complicated by the fact that you have many things you have to work on simultaneously,” the chief U.S. diplomat said. “We will continue to do that even as we are obviously concerned with what happened with Mr. Snowden.”

Wang, the Chinese foreign minister, told reporters that his government had urged North Korea to give up its nuclear weapons program. He called for early resumption of six-party talks on the issue, which include the United States and China as well as the two Koreas, Japan and Russia.

Kerry also discussed North Korea in a trilateral meeting with the foreign ministers of South Korea and Japan. The country’s nuclear program will be on the agenda — along with the ongoing conflict in Syria — in Kerry’s meeting with Lavrov, their first face-to-face encounter since President Obama decided to send military supplies to Syrian rebels fighting against the Russian-backed government of President Bashar al-Assad.

Active participation in regional groups such as ASEAN is a major pillar of the Obama administration’s attempt to “rebalance” U.S. foreign and trade policy toward Asia.

Regional security is a significant component of the Brunei meetings. Kerry and his predecessor, former secretary of state Hillary Rodham Clinton, have strongly supported peaceful resolution of the long-standing dispute between Southeast Asian nations and China over the maritime routes and resources in the South China Sea.

Repeated clashes have occurred between China and other seagoing nations in the region. Countries such as the Philippines have sought closer military ties with the United States to help preserve their interest in the waterways.

A modest advance toward settlement was made Sunday, when Asian ministers agreed to China’s request for a special board of experts to oversee the writing of a binding code of conduct for the ocean passages, where the United States has carried out naval maneuvers in apparent response to Chinese military patrols.

“As a Pacific nation, and the resident power, the United States has a national interest in the maintenance of peace and stability, respect for international law, unimpeded lawful commerce and freedom of navigation in the South China Sea,” Kerry said in a speech to ASEAN conference delegates.

“While we do not take a position on a competing territorial claim over land features, we have a strong interest in the manner in which the disputes of the South China Sea are addressed and in the conduct of the parties,” he said.

Asked how Obama could claim a “pivot” toward Asia when his administration appears to be devoting much of its time and attention to the Middle East and Europe, Kerry responded adamantly.

“I’m here. This is my second visit” to the region, he said, adding that Obama, Vice President Biden and Defense Secretary Chuck Hagel also have traveled to Asia recently and plan to return.

“I want you to be absolutely confident: Over the next 3 1 / 2 years of the Obama presidency, you will see energized and serious engagement in continuing the rebalance efforts.”

DeYoung reported from Brunei. Michael Birnbaum contributed to this report from Berlin.