Jeff Sessions says government will go after those who leak classified information

U.S. Attorney General Jeff Sessions gives a stern warning to those in the intelligence community and other unauthorized persons about leaking classified information, stating the Department of Justice is "open for business."

News conference comes a day after transcripts of Trump phone calls to foreign leaders made public

U.S. Attorney General Jeff Sessions promises prosecutions to the fullest extent of the law for those who leak classified material threatening national security. (Andrew Harnik/Associated Press)

U.S. Attorney General Jeff Sessions gives a stern warning to those in the intelligence community and other unauthorized persons about leaking classified information, stating the Department of Justice is "open for business."

Sessions said he condemned "in the strongest terms the staggering number of leaks undermining the ability of our government to protect this country."

"We are taking a stand," said Sessions. Both he and Dan Coats, the director of national intelligence, said those caught would be prosecuted to the full extent of the law.

Sessions and Coats did not take questions from reporters, but Sessions said the department is reviewing guidelines related to subpoenas of journalists, leaving open the question of whether members of the media will face more pressure to reveal sources.

While every White House administration has dealt with leaks, the Trump administration in its first six months has been particularly plagued.

Through reporting from sources close to the administration, the New York Times and Washington Post have produced new information on contacts between Trump's campaign and transition team and the Russia government.

The Post on Thursday also reported from transcripts the paper had obtained of conversations Trump had shortly after becoming president with the leaders of Australia and Mexico.

In the reportedly testy exchange with Aussie PM Malcolm Turnbull, Trump appears to have little knowledge of a refugee exchange agreement between the two countries, pertaining to people detained in Papua New Guinea but not allowed into Australia. Meanwhile, Trump reportedly beseeched Mexican President Enrique Pena Nieto to stop declaring publicly that Mexico would not pay for a border wall.

Sessions referenced that Washington Post report, saying it undermined the ability of world leaders to "talk freely in confidence."

Sessions said four people have been charged this year with unlawfully disclosing classified material or concealing contacts with foreign intelligence officers. The list includes a 26-year-old woman charged in connection with a report on Russian phishing emails targeting U.S. election officials last year.

Coats said the leaks threatened national security, and that some emanated from the executive branch as well as Congress.

The source for at least one story is well known. Former FBI director James Comey, in public testimony on Capitol Hill weeks after he was fired by Trump, admitted that through a friend at Columbia University, he helped source a story published by the New York Times through memos of a meeting with Trump.

Comey said he did so because he feared Trump would lie about the details of their meeting, something he hadn't feared with respect to meetings with Barack Obama and George W. Bush.

Obama White House stepped up cases

Trump, meanwhile, has flatfooted the media with claims that recordings of his conversations with Comey might exist — a claim he later denied — and that predecessor Obama and his top official, Susan Rice, had a hand in wiretapping Trump Tower.

Trump also was accused of revealing classified information to visiting Russians.

Donald Trump Jr., meanwhile, spoke publicly about emails regarding a meeting with a Russian contact when it was evident they had been acquired and were soon to be published by the New York Times.

The show of force by the attorney general will undoubtedly please the president, who has both railed against leaks and publicly criticized Sessions for recusing himself in investigations related to Russia.

Coats stressed that individuals with access to classified information who had "legitimate concerns" could follow existing provisions regarding whistleblowing or contact congressional intelligence committees.

Media organizations also had an often-tense relationship with the Obama administration, whose Justice Department brought more leaks cases than all his predecessors combined and was criticized for manoeuvre seen as needlessly aggressive and intrusive.

That included a secret subpoena of phone records of Associated Press reporters and editors following a 2012 story about a foiled bomb plot, and the labeling of a Fox News journalist as a "co-conspirator" after a report on North Korea. The Justice Department also abandoned a years-long effort to reveal his source in the trial of an-ex CIA officer who was later found guilty of disclosing classified information.

Following consultation with media lawyers, the department in 2015 revised its guidelines for leak investigations to require additional levels of approval before a reporter could be subpoenaed

With files from The Associated Press