The United States is not aware of any specific threat to the U.S. homeland from Islamic State militants, the Department of Homeland Security said on Friday after Britain raised its international terrorism threat level.
Islamic State militants and their supporters, however, "have demonstrated the intent and capability to target American citizens overseas," Homeland Security Secretary Jeh Johnson said in a statement. He noted DHS has taken steps over the summer to strengthen security at overseas airports with direct flights to the United States.