WASHINGTON — Eager to quell a domestic furor over U.S. spying, the nation’s top intelligence official stressed Saturday that a previously undisclosed program for tapping into Internet usage is authorized by Congress, falls under strict supervision of a secret court and cannot intentionally target a U.S. citizen. He decried the revelation of that and another intelligence-gathering program as reckless.

For the second time in three days, Director of National Intelligence James Clapper took the rare step of declassifying some details of an intelligence program to respond to media reports about government counterterrorism techniques.

“Disclosing information about the specific methods the government uses to collect communications can obviously give our enemies a ‘playbook’ of how to avoid detection,” he said in a statement.

Clapper said the data collection under the program, first unveiled by the newspapers The Washington Post and The Guardian, was with the approval of the secret Foreign Intelligence Surveillance Act Court and with the knowledge of Internet service providers. He emphasized that the government does not act unilaterally to obtain that data from the servers of those providers.

Clapper’s reaction came a day after President Barack Obama defended the counterterrorism methods and said Americans need to “make some choices” in balancing privacy and security. But the president’s response and Clapper’s unusual public stance underscore the nerve touched by the disclosures and the sensitivity of the Obama administration to any suggestion that it is trampling on the civil liberties of Americans.

Clapper’s statement and declassification Saturday addressed the Internet scouring program, code-named PRISM, that allowed the NSA and FBI to tap directly into the servers of major U.S. Internet companies.