"We have made clear that anyone who touches it, anyone who supports it, anyone who allows a ship to dock is at risk of receiving sanctions from the United States," Pompeo told reporters. "If that ship again heads to Syria we will take every action we can consistent with those sanctions to prevent that."

The Adrian DArya - formerly the Grace 1 - left Gibraltar on Aug. 18 and ship-tracking data showed the vessel was heading toward the Greek port of Kalamta.