US Attorney General Jeff Sessions has announced four people have been charged over leaks as he launched a crackdown on disclosure of classified material.
He said the suspects stood accused of unlawfully divulging classified information or concealing contacts with foreign intelligence officers.
America’s top prosecutor said the administration has tripled the number of active leak probes since January.
President Donald Trump has criticised Mr Sessions for not dealing with leaks.
‘Leak referrals exploding’
At Friday’s news conference, Mr Sessions said no government can be effective when its leaders cannot talk freely in confidence with foreign leaders.
He said there had been a “dramatic” increase in recent months of unauthorised disclosures to the media and even foreign adversaries.
“Referrals for investigations of classified leaks to the Department of Justice from our intelligence agencies have exploded,” he said.
The attorney general also said he wanted to review policies on media subpoenas – compelling journalists to testify in court – to balance the role of the press with protecting national security.
The move is likely to send a chill through US newsrooms that have been breaking almost daily scoops attributed to unnamed sources, which have embarrassed the White House.
Mr Sessions was joined by Director of National Intelligence Dan Coats, who issued a stark warning to leakers.
“Anyone who engages in these criminal acts is betraying the intelligence community and the American people,” he said.
“We feel the pain of those betrayals intensely and I can assure you that I will do everything in my power as director of national intelligence to hold those people accountable.
“Understand this, if you improperly disclose classified information, we will find you, we will investigate you, and we will prosecute to the fullest extent of the law, and you will not be happy with the result.”
~ Salvador Dali