In a speech at the US Justice Department Mr Obama sought to reassure American allies, saying: "The leaders of our close friends and allies deserve to know that if I want to learn what they think about an issue, I will pick up the phone and call them, rather than turning to surveillance." Addressing privacy concerns: US President Barack Obama speaks about the surveillance techniques used by the NSA. Credit:AFP He also detailed what sort of intelligence America would pursue and how it would – or would not – be used. "The United States does not collect intelligence to suppress criticism or dissent, nor do we collect intelligence to disadvantage people on the basis of their ethnicity, race, gender, sexual orientation, or religious beliefs. And we do not collect intelligence to provide a competitive advantage to US companies, or US commercial sectors," he said. "In terms of our bulk collection of signals intelligence, US intelligence agencies will only use such data to meet specific security requirements: counter-intelligence; counter-terrorism; counter-proliferation; cyber-security; force protection for our troops and allies; and combating transnational crime, including sanctions evasion."

And he said the US would take the "unprecedented step" of extending some privacy protections to foreign citizens, including limiting the time its agencies can hold personal information and restricting its use. But the President showed no sign the US was softening its attitude towards Mr Snowden, whose leaks prompted the public debate over the NSA that led to the reforms. "Given the fact of an open investigation, I'm not going to dwell on Mr Snowden's actions or motivations," he said. "I will say that our nation's defence depends in part on the fidelity of those entrusted with our nation's secrets. If any individual who objects to government policy can take it in their own hands to publicly disclose classified information, then we will never be able to keep our people safe, or conduct foreign policy." He said the sensational way in which the disclosures had "often shed more heat than light" had damaged America's intelligence gathering operations "in ways that we may not fully understand for years to come".

I will pick up the phone and call them, rather than turning to surveillance Mr Obama mounted a defence of the NSA and American intelligence operations. "Now let me be clear: our intelligence agencies will continue to gather information about the intentions of governments – as opposed to ordinary citizens – around the world, in the same way that the intelligence services of every other nation does. We will not apologise simply because our services may be more effective," he said. And he said it could be frustrating that America was held to a higher standard than other world powers. "No one expects China to have an open debate about their surveillance programs, or Russia to take the privacy concerns of citizens into account. But let us remember that we are held to a different standard precisely because we have been at the forefront in defending personal privacy and human dignity." Speaking shortly before Mr Obama made his address, Glenn Greenwald, the journalist who published Mr Snowden's leaks, accused the President of engaging in a publicity stunt.

"It's really just basically a PR gesture, a way to calm the public and to make them think there's reform when in reality there really won't be. And I think that if the public, at this point, has heard enough about what the NSA does and how invasive it is, that they're going to need more than just a pretty speech from President Obama to feel as though their concerns have been addressed," he told Al Jazeera America. Another critic of the program, Democratic senator Mark Udall, said he was pleased by the changes, tweeting: "After my years of bipartisan work and ongoing efforts, President Obama took big steps forward today on NSA reform." Rand Paul, the libertarian Republican senator who has led Congressional opposition to the NSA's programs, said he was disappointed by the changes, telling Politico they resulted in "the same unconstitutional program with a new configuration". WikiLeaks founder Julian Assange, still occupying Ecuador's London embassy, CNN: "It's embarrassing for a head of state like that to go on for almost 45 minutes and say almost nothing."

All data searches now require approval by a court.

Records only be examined if a contact is two, rather than three, steps removed from a phone number connected to a suspected terrorist organisation.

Government will not hold bulk metadata.

It will not monitor communications of close allies without "compelling national security purpose".

Secret data requests to private entities will no longer be "indefinite" but "terminate within a fixed time."

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