The Department of Justice has since January charged four people with disclosing classified information or concealing contacts with federal officers, US Attorney General Jeff Sessions said in a news conference on Friday.
Sessions also said that the US Department of Justice is reviewing policies concerning subpoenas for the press about intelligence leaks.
"We’ve already charged four people with unlawfully disclosing classified material or with concealing contacts with federal officers," Sessions stated.
"One of the things we are doing is reviewing policies affecting media subpoenas," Sessions stated.
"We respect the important role that the press plays and will give them respect, but it is not unlimited, they cannot place lives at risk without impunity."
Meanwhile, Director of National Intelligence Dan Coats said that leaks of classified information come from outside the Intelligence Community as well as from within, and include material shared by the executive branch and the US Congress.
"These national security breaches do not just originate in the intelligence community," Coats stated.
"They come from a wide range of sources within the government including the executive branch and including the Congress."
"We are prepared to take all necessary steps to…identify individuals who illegally expose and disclose classified information [and] forward information about their deeds to the FBI for full investigation," Coats said.
The director explained the ODNI and Justice Department would work closely together to prosecute anyone who discloses classified material.
Coats said he would also not hesitate to use his authority as national intelligence director to "deal with" people within the Intelligence Community who leak classified information.
Furthermore, Coats said the National Counterintelligence and Security Center is reviewing current policies as well as security clearance procedures.
In July, US President Donald Trump said during a press conference that Sessions should get tougher on dealing with ongoing leaks, which seemingly originate in the Justice Department.
Later, former White House Communications Director Anthony Scaramucci said that he and Trump have a "very good idea" who the leakers are.
Previously, in a Twitter message about leaks, Scaramucci copied former White House Chief of Staff Reince Priebus.
Trump has repeatedly said that leaks threaten the US national security and called for finding those who share classified information with the press.