Curbing of US spy powers 'historic': Edward Snowden

US Senate has passed a landmark legislation that limits the power of NSA

Fugitive former US security contractor Edward Snowden has hailed as "historic" efforts to end the bulk collection of Americans' phone records, while urging campaigners to go further.

The United States Senate passed landmark legislation that limits the powers of the National Security Agency, where Snowden was a contractor before he began leaking details of vast government spying programmes in 2013.

Speaking by live video link from Russia at an Amnesty International event in London yesterday shortly before the bill was passed, Snowden called efforts to end mass surveillance "not enough" but "an important step".

"This is meaningful, it is important and actually historic that this has been refuted, not just by the courts, but by Congress as well and the president himself is saying this mass surveillance has to end," Snowden said.

"For the first time in recent history we found that despite the claims of government, the public made the final decision and that is a radical change that we should seize on, we should value and we should push further."

The USA Freedom Act halts the NSA's dragnet of telephone data from millions of Americans with no connection to terrorism -- the most controversial surveillance programme among several signed into law after the 9/11 attacks on the United States in 2001.

The bill, which must now be signed into law by President Barack Obama, allows authorities to access information from telephone companies only with a warrant from a secret counterterror court.

It also re-instates powers that expired on Sunday, including roving wiretaps and lone-wolf tracking.

Snowden heavily criticised the mass collection of data, arguing it was ineffective in preventing terror attacks while eroding public freedom.

"If we collect everything we understand nothing," Snowden told the audience. "We're spending resources for no benefit in terms of public safety and a real cost in terms of freedom and liberty."

"Once you've lost a certain degree of power you can no longer oppose that power. There can be no revolutionary political movement when the government knows what everybody is doing, what everybody is saying, what everybody is thinking."

Snowden, who currently lives in Russia because he has temporary asylum there, told the audience he had applied to 21 countries including in western Europe for asylum.

"I'm still waiting on them to get back to me," he added, to laughter from the audience.