“We were aware of U.S. citizen Douglas McAuthur McCain’s presence in Syria and his death," National Security Council spokeswoman Caitlin Hayden said in a statement.
“We continue to use every tool we possess to disrupt and dissuade individuals from traveling abroad for violent jihad and to track and engage those who return,” she added.
Rebels trying to oust Syrian President Bashar Assad, part of the Free Syrian Army, killed McCain, 33, of San Diego, according to an NBC News report that also said that ISIS has recruited dozens of U.S.-born jihadists to join their ranks.
McCain’s confirmed presence in Syria comes amid fears that an unknown number of ISIS fighters with Western passports could use them to return to the U.S. and Europe to launch terrorist attacks.
A U.S. passport was found near his body, NBC reported.
The White House in recent days said U.S. intelligence sources have determined that ISIS is not actively plotting an attack on U.S. soil but that could change quickly.
Rep. Mike Rogers, R-Mich., who chairs the House Intelligence Committee, told NBC News Sunday that ISIS has fighters who are just “one plane ticket away from U.S. shores – that’s why we’re so concerned about it.”
He said estimates of the number of ISIS fighters with Western passports range from 2,000 to far higher.
“Intelligence [officials] have a very different number, and it’s much higher than that,” he said.