A secret US intelligence court has renewed an order to continue seeking hundreds of millions of telephone records of Americans in its search for foreign terror or espionage suspects, the US government says.
The order issued on Friday by the Foreign Intelligence Surveillance Court has been in place for years, but must be renewed every three months.
It was exposed in June after former National Security Agency contractor Edward Snowden leaked details of two top secret US surveillance programmes that critics say violate privacy rights.
The order was set to expire on Friday, and its renewal shows that the Barack Obama administration and the court of 11 federal judges stand behind its legality.
In a statement, the office of national intelligence director James Clapper said it was confirming the renewal as part of an ongoing effort to make more information about the recently declassified programmes as public as possible.
Clapper "has decided to declassify and disclose publicly that the government filed an application with the Foreign Intelligence Surveillance Court seeking renewal of the authority to collect telephony metadata in bulk, and that the court renewed that authority," the statement said.
Fills an intelligence gap
The two programmes, both run by the NSA, pick up millions of telephone and Internet records that are routed through American networks each day.
Intelligence officials say they have helped disrupt dozens of terrorist attacks, and target only foreign suspects outside the United States while taking close care not to look at the content of conversations or messages by American citizens.
But they have raised sharp concerns about whether the US is improperly, or even illegally, snooping on people at home and abroad.
The government also defended the phone-tracking programme in a letter to a federal judge, saying it is monitored by all three branches of the government.
The letter sent on Thursday by assistant US attorneys in Manhattan said the "highly sensitive and, in many respects, still classified intelligence-collection programme" required the collection and storage of a large volume of information about unrelated communications to fight terrorism.
The letter, the first government response to a lawsuit filed by the American Civil Liberties Union against the Obama administration earlier this year, said the programme "fills an intelligence gap highlighted by the attacks
of 9/11" and had been repeatedly approved by multiple judges.
The ACLU had asked a judge to find the programme unconstitutional, saying the government's programme exceeds the Congressional authority provided by the Patriot Act, which Congress hurriedly passed after the September 11 attacks and reauthorised in 2005 and 2010.
Snowden has been charged with espionage and is seeking asylum from several countries, including Russia.
The US whistleblower has been holed up for more than three weeks in a transit zone at Moscow's international airport since arriving from Hong Kong, and Russian customs inspectors say they do not have jurisdiction to seize him.