Washington, August 5 (RHC)-- U.S. Attorney General Jeff Sessions has pledged to clamp down on people who leak government’s classified information after President Donald Trump called his actions on leakers “very weak.”

"I strongly agree with the president and condemn in the strongest terms the staggering number of leaks undermining the ability of our government to protect this country," Sessions told a press conference on Friday.

Since Trump took office in January, government leaks have tripled and Sessions says such leaks extremely undercut U.S. national security. Justice Department officials, who are currently reviewing guidelines aimed at making it hard for the government to subpoena reporters about their sources, said there was a possibility that journalists could be prosecuted.

"No one is entitled to surreptitiously fight their battles in the media by revealing sensitive government information," Sessions said, adding: "No government can be effective when its leaders cannot discuss sensitive matters in confidence or to talk freely in confidence with foreign leaders."

Sessions revealed that, so far, four people have been arrested and charged with "unlawfully disclosing" confidential information or concealing contacts with federal officers.

Meanwhile, a White House adviser suggested that there could be lie detector tests for staff people who have access to transcripts of Trump's phone calls.  

On Thursday, The Washington Post published transcripts of conversations between Trump and his Mexican and Australian counterparts. Sessions also said that he would reinforce a task force formed during former president Barack Obama's administration to apprehend leakers.

Under Obama, whistleblowers and leakers, who had talked to journalists, were prosecuted and the Justice Department issued subpoenas to journalists to force them to reveal their sources. "We will not allow rogue anonymous sources with security clearances to sell out our country," Sessions said. "They cannot place lives at risk with impunity," he added. "We must balance the press's role with protecting our national security."

His remarks came just hours after The Wall Street Journal reported that U.S. Special Counsel Robert Mueller tasked with investigating alleged Russian interference in the 2016 US presidential election had reportedly impaneled a grand jury, whose proceedings are typically secret.