A senior US intelligence official has told a House committee that discerning foreign leaders' intentions is a key goal of US spying operations.
Director of National Intelligence James Clapper was appearing before the House of Representatives Intelligence Committee on Tuesday.
He said spying on foreign leaders was a basic tenet of intelligence operations, but the United States does not indiscriminately spy on other nations.
Mr Clapper was reacting to a growing international row over reports the US eavesdropped on foreign allies, the BBC reports.
"Leadership intentions is kind of a basic tenet of what we collect and analyse," Mr Clapper said, adding that foreign allies spy on US officials and intelligence agencies as a matter of routine.
Also testifying before the House intelligence committee was National Security Agency (NSA) Director General Keith Alexander, who called media reports in France, Spain and Italy that the NSA gathered data on millions of telephone calls "completely false".
The information "that lead people to believe that the NSA or United States collected that information is false, and it's false that it was collected on European citizens," he added. "It was neither."
General Alexander told the committee that all those working for the NSA were putting the safety of Americans first and operating within the law.
"These are patriots who every day come to work saying how can we defend this country and protect civil liberties and privacy. Nothing that has been released has shown that we're trying to do something illegal or unprofessional.
"When we find a mistake, a compliance issue, we report it to this committee, to all our overseers and we correct it."
General Alexander said much of the data cited by non-US news outlets was actually collected by European intelligence services and later shared with the NSA.
The testimony on Capitol Hill came amid a series of reports in the international news media that the NSA had spied extensively on the leaders, diplomats and citizens of nations friendly to the US, including Brazil, France, Germany, Mexico and Spain.
The revelations stem from documents leaked by fugitive ex-US intelligence contractor Edward Snowden, who now lives in Russia and is wanted in the US in connection with the unauthorised disclosures.
Tuesday's House hearing followed calls by US Senate intelligence committee chairwoman Dianne Feinstein to end eavesdropping on leaders of the nation's allies.
"It is my understanding that President Obama was not aware Chancellor Merkel's communications were being collected since 2002. That is a big problem."
President Barack Obama has faced significant criticism over reports he was unaware of the extent of the spying.
In one of the most significant disclosures, German media have reported that the US bugged German Chancellor Angela Merkel's phone for more than a decade - and that the surveillance only ended a few months ago.