Sessions warns of crackdown on US government leakers, media sources

US Attorney-General Jeff Sessions went on the attack against a "culture of leaking" on Friday, warning of a possible crackdown both on reporters and their sources inside the federal government.

Sessions in recent weeks has been publicly criticised by US President Donald Trump for his performance in the job, including for what Trump called his weakness on the issue of going after leakers.

In a move derided by critics as an attack on the free press, Sessions said the administration was reviewing policies on forcing journalists to reveal their sources.

"So, today, I have this message for the intelligence community: The Department of Justice is open for business. And I have this warning for would-be leakers: Don't do it," Sessions said.

"Since January, the Department has more than tripled the number of active leak investigations compared to the number pending at the end of the last Administration."

He also told the employees of government agencies to stop leaking and called the issue a matter of national security.

Some have been related to probes into Russian meddling in the 2016 US presidential election; others have concerned infighting in the White House.

"One of the things we are doing is reviewing policies affecting media subpoenas," Sessions told reporters as he announced administration efforts to battle what he called a "staggering number of leaks undermining the ability of our government to protect this country."

"We respect the important role that the press plays and will give them respect, but it is not unlimited," the nation's top law official said.

Trump has repeatedly criticised news outlets and their work as "fake news," and administration officials have criticised the use of anonymous sources, a standard journalistic practice.

TRT World's Tetiana Anderson reports.

"Culture of leaking must stop"

The Justice Department has tripled the number of investigations into unauthorised leaks of classified information and four people have already been charged, Sessions said.

Sessions did not immediately give the identities of the four people charged.

He said they had been accused of unlawfully disclosing classified information or concealing contacts with foreign intelligence officers.

"We are taking a stand," said Sessions, adding "this culture of leaking must stop."

But it is difficult to prosecute members of the news media in the US for publishing leaked information.

It is not illegal to leak information, as such, but divulging classified information is against the law.

Some of the more high-profile leaks in the Trump administration have revealed White House infighting in articles that would appear not to involve divulging classified information.

In the latest major leak to the media, the Washington Post published transcripts on Thursday of contentious phone calls that Trump had in the early days of his administration with Mexican President Enrique Pena Nieto and Australian Prime Minister Malcolm Turnbull.

"No government can be effective when its leaders cannot discuss sensitive matters in confidence or to talk freely in confidence with foreign leaders," Sessions said of that case.

Deputy Attorney General Rod Rosenstein told reporters the department was just starting to review the policy on media subpoenas and could not say yet how it might be changed.

But he did not rule out the possibility of threatening journalists with jail time.

Rosenstein did not give the exact number of leak investigations the Justice Department is currently handling.

The most recent case, and the first under Trump, was the Justice Department's indictment in June of Reality Leigh Winner, 25, a US intelligence contractor accused of leaking a classified National Security Agency report about Russia's alleged interference in the 2016 election.