Obama pledges surveillance changes
President Barack Obama has announced a series of steps to ease fears about the scope of secret domestic and foreign surveillance activities.
But he did not say he was ready to end the massive collection of information about Americans' telephone calls and emails.
Mr Obama also explained to reporters his decision to cancel a summit next month with Russian leader Vladimir Putin. The US president said he had only "mixed" success in moving forward in resetting the relationship with Russia.
Mr Obama said Russia's decision to grant asylum to National Security Agency leaker Edward Snowden was not the sole reason for calling off the meeting with Mr Putin. He encouraged Mr Putin to "think forward instead of backwards" on a long list of issues that will define currently strained relations in the future.
In wide-ranging comments lasting nearly an hour, Mr Obama also said it would not be appropriate to boycott the upcoming Winter Olympics in Sochi, despite Russian laws that discriminate against gays and lesbians.
The President also said he did not consider Snowden, who is charged in federal court with violations of the Espionage Act, as a whistleblower or "patriot". He invited Snowden, if he feels what he did was legal and right, to return to the United States to defend his actions.
Addressing the issues raised by Snowden's leaks of secret government surveillance programmes, Mr Obama said the world needs to be convinced that US espionage does not step on their rights.
One goal of the news conference was to try to calm anger over a spying programme that has been kept secret for years and that the administration falsely denied ever existed. The administration was releasing more information about how it gathers intelligence at home and abroad, plus the legal rationale for the bulk collection of phone records without individual warrants. That programme was authorised under the USA Patriot Act, which Congress hurriedly passed after the September 11 2001 terrorist attacks.
The National Security Agency says phone records are the only things it collects in bulk under that law. But officials have left open the possibility that it could create similar databases of people's credit card transactions, hotel records and internet searches.
The changes Mr Obama has endorsed include the formation of an outside advisory panel to review US surveillance powers, assigning a privacy officer at the National Security Agency, and the creation of an independent attorney to argue against the government before the nation's surveillance court. All those new positions would carry out most of their duties in secret.