The chairwoman of the Senate Intelligence committee says the top secret court order for telephone records of millions of U.S. customers of Verizon is a three-month renewal of an ongoing practice.

Democratic Sen. Dianne Feinstein of California spoke to reporters at a Capitol Hill news conference on Thursday after the Obama administration defended the National Security Agency's need to collect the records.

Other lawmakers have said previously that the practice is legal under the Patriot Act although civil libertarians have complained about U.S. snooping on American citizens.