An American citizen who fought for the Islamic State in Syria and surrendered to the Syrian Democratic Forces (SDF) was turned over to U.S. forces according to the U.S. Department of Defense.

In a released statement, U.S. military officials said earlier that an American citizen who was fighting with ISIS and surrendered on September 12 is now “being legally detained by Department of Defense personnel as a known enemy combatant.”

A U.S. official told ABC News that the individual is still overseas, as the Department of Justice and the Trump administration determine how to move forward.

The Department of Defense has referred all questions about the incident to the State Department and Department of Justice. But during a State Department briefing on Thursday, spokesperson Heather Nauert said she had no further information on the individual’s circumstances, saying anyone who would fight for ISIS is “dumb.”

“It serves as a good reminder that in a nation of 330-some million people, some people will be dumb enough to go to Iraq and Syria to try to fight for ISIS,” Nauert said, adding, “You can’t be very bright if you’re going over there and doing that.”

The US government’s official policy is not to support any citizen’s desire to travel to Syria or Iraq to join the conflict on either side. Although they do monitor any attempts to support the terrorist groups of the Islamic State or al-Qaeda.

US intelligence officials estimate that more than 250 Americans have either traveled to Syria or Iraq, or attempted to travel to Syria or Iraq, to join the Islamic State. Many have cited the recruitment videos that ISIS produces as a major catalyst in joining.