https://sputniknews.com/asia/201801131060722222-japan-patrols-north-korea-stop-fuel/
TOKYO (Sputnik) - Japan’s Maritime Self-Defense Force has been patrolling the waters off North Korea to warn off ships trying to smuggle fuel in breach of UN sanctions, military officials told local media Saturday.
Japanese military sources told the Kyodo news agency that warships have been monitoring the Sea of Japan and the Yellow Sea east and west of the Korean Peninsula at the request of the US since last month.