(CNN) -- The U.S. government has obtained a top secret court order that requires Verizon to turn over the telephone records of millions of Americans to the National Security Agency on an "ongoing daily basis," the UK-based Guardian newspaper reported Wednesday.
The four-page order, which The Guardian published on its website, requires the communications giant to turn over "originating and terminating" telephone numbers as well as the location, time and duration of the calls. The order, published on the newspaper's website, does not require the contents of conversations to be turned over.
CNN has so far been unable to independently verify the authenticity of the document.
If genuine, the order gives the NSA blanket access to the records of millions of Verizon customers' domestic and foreign phone calls made between April 25, when the order was signed, and July 19, when it expires.
Verizon spokesman Edward McFadden declined to comment on the report.
According to the document published by The Guardian, Foreign Intelligence Surveillance Act (FISA) Court Judge Roger Vinson signed a "Secondary Order" granting an FBI request for access to the records.
The FBI did not respond to a CNN request for comment. The NSA told CNN said it will respond "as soon as we can."
The order does not say why the request was made, but it bans the government and Verizon from making the contents public.
"As far as we know, this order from the FISA court is the broadest surveillance order to ever have been issued: it requires no level of suspicion and applies to all Verizon subscribers anywhere in the U.S.," the Center for Constitutional Rights said in a statement released shortly after the story broke.
"It also contains a gag order prohibiting Verizon from disclosing information about the order to anyone other than their counsel."
Former Vice President Al Gore also criticized the move.
"In the digital era, privacy must be a priority. Is it just me, or is secret blanket surveillance obscenely outrageous?" he said in a post on Twitter.
The order is allowed under the Patriot Act, and it is not the first time such an action has been taken.
In 2006, it was revealed that the NSA was secretly collecting telephone records as part of an effort to root out potential terror plots.
Reacting to Wednesday's disclosure, the American Civil Liberties Union called for an immediate end to the order and a congressional investigation into the move.
"It's a program in which some untold number of innocent people have been put under the constant surveillance of government agents," Jameel Jaffer, the ACLU's deputy legal director, said.
"It is beyond Orwellian, and it provides further evidence of the extent to which basic democratic rights are being surrendered in secret to the demands of unaccountable intelligence agencies."
The news about the Verizon order comes as the Obama administration is under fire following revelations that the Justice Department seized two months of telephone records of a number of Associated Press reporters and editors, saying the requests were part of an investigation into the leak of classified information.
Justice officials haven't specified the leak that triggered the probe, but the AP has said it believes the investigation focuses on its account of a foiled plot to bomb a U.S. airliner in May 2012.
CNN's Adam Levine, Jake Tapper, Carol Cratty, William Mears and Sara Pratley contributed to this report.