The government Friday reasserted its claim of state-secrets privilege to keep under wraps what it says are operational details in two long-running lawsuits alleging the National Security Agency's surveillance of Americans' emails and phone calls is unlawful.

Federal officials also for the first time publicly acknowledged that President George W. Bush in 2001 authorized sweeping collections of Americans' phone and Internet data — programs that operated for years solely under executive power before being brought under court and congressional oversight.

Director of National Intelligence James Clapper said in a court filing Friday that Bush authorized the collection efforts on Oct. 4, 2001, shortly after the Sept. 11 terrorist attacks.