“It is not standard practice for the United States to send in the U.S. military” into war zones to extract American citizens, Sullivan said, speaking at a press briefing at the White House on Monday. “We didn’t do it in Libya. We didn’t do it in Yemen, and no we didn’t do it in Ukraine. Afghanistan was a unique case involving the end of the 20-year war that the United States was centrally involved in,” he added. According to the Associated Press, an estimated 16,000 private U.S. citizens are registered with the embassy as being in Sudan.