WASHINGTON - Attorney General Jeff Sessions pledged to rein in government leaks that he said undermine US security, taking an aggressive public stand after being called weak on the matter by President Donald Trump.

The nation's top law enforcement official cited no current investigations in which disclosures of information had jeopardized the country, but said the number of criminal leak probes had more than tripled in the early months of the Trump administration.

Justice Department officials also said they were reviewing guidelines put in place to make it difficult for the government to subpoena journalists about their sources, and would not rule out the possibility that a reporter could be prosecuted.

"No one is entitled to surreptitiously fight to advance their battles in the media by revealing sensitive government information," Sessions said in an announcement that followed a series of news reports this year on the Trump campaign and White House that have relied on classified information.

"No government can be effective when its leaders cannot discuss sensitive matters in confidence or talk freely in confidence with foreign leaders."

Media advocacy organizations condemned the announcement, with Bruce Brown, the executive director of the Reporters Committee for Freedom of the Press, saying the decision to review existing guidelines was "deeply troubling".

Meanwhile, a White House adviser raised the possibility of lie detector tests for the small number of people in the West Wing and elsewhere with access to transcripts of Trump's phone calls. The Washington Post on Thursday published transcripts of his conversations with the leaders of Mexico and Australia.

Associated Press