WASHINGTON — The Justice Department’s top national security official is leaving his position next month, the department announced Tuesday.

John Carlin, who has led the department’s national security division since 2014, will be leaving government on Oct. 15.

The department did not reveal what Carlin, 43, plans to do next, but it said he would take some time off and spend time with his family.

“John Carlin has been a trusted and tireless leader of the Justice Department’s National Security Division,” Attorney General Loretta Lynch said in a statement. “He is wholly devoted to the department’s most important mission — protecting our country against acts of terrorism and other national security threats — and he has set a high standard by relentlessly pursuing those who seek to harm our people and threaten our assets.”

Carlin’s exit leaves the Obama administration without one of its most vocal advocates for publicly identifying and blaming foreign government hackers for cyberattacks on American institutions. His departure comes as the administration weighs whether and how to respond to a Democratic National Committee cyberbreach that U.S. officials believe was committed by the Russians.

During his tenure, the Justice Department brought indictments against five Chinese military officials accused of hacking into American corporations in a case of economic espionage. The department this year also secured indictments of Iranian hackers accused of digital intrusions on banks and a small dam outside New York City.

It’s unclear whether those actions will result in courtroom prosecutions, but Carlin has repeatedly encouraged the use of indictments and other sanctions as a deterrent against foreign hackers and the nations that sponsor them and said such cases were effective.

Other notable prosecutions brought by national security division lawyers under Carlin’s watch include the case against Ardit Ferizi, a computer hacker who helped the Islamic State group by providing names of U.S. government and military workers as potential targets. They also prosecuted members of the so-called Syrian Electronic Army, who have been charged with computer hacking-related conspiracies that targeted the U.S. government, media and private-sector companies.

The division has also overseen the prosecutions of young Americans who have lent support to the Islamic State.

Carlin previously served as chief of staff and senior counsel to former FBI director Robert Mueller and was also a federal prosecutor in Washington.