NEW : Russian Foreign Ministry urges South Korea and South Korea to call off military drill . the next five days drill on Yeonpyeong Isand resulted shelling by Koreas , 18 deaths . North Korea says it will deliver a `` self-defensive blow '' to the South if military exercise takes place . `` If North Korea were to react to that in a negative way and fire back at those firing positions on the islands , that would start potentially a chain reaction of firing and counter-firing . '' Yeonpyeong Island is a flashpoint between the United States .
NEW : Russian Foreign Ministry urges South Korea and South Korea to call off military drill . the next five days drill on Yeonpyeong Isand resulted shelling by Koreas , 18 deaths . North Korea says it will deliver a `` self-defensive blow '' to the South if military exercise takes place . Yeonpyeong Island is a flashpoint between the United States .