The Coast Guard led the second and final day of the exercise, focusing on field maneuvers under the scenario of infiltrations by non-military entities, which followed the Navy-led drills on Sunday that were designed to better fend off foreign military threats.

For Monday's drills, nine vessels from the Coast Guard and the Navy, as well as warplanes and special forces, were mobilized. On Sunday, the military mobilized 10 naval vessels, including its 7,600-ton Aegis-equipped destroyer, Sejong the Great, for the first time and 10 warplanes, such as F-15Ks.

The drills, launched in 1986, usually have been held in June and December, but this year's drills were pushed back over apparent concern they could excessively aggravate tensions with Tokyo. Japan, which has made territorial claims to Dokdo, has protested the drills.

Launching the exercise, South Korea gave it a new name, the "East Sea Territory Protection Exercise," instead of its previous name of the Dokdo Defense Drills, which reflects "the significance and the scale of this exercise that aims to further consolidate the determination to defend our territories in the East Sea, including Dokdo," the Navy said.

The drills also came after a Russian warplane violated the Korean airspace above the islets last month.

Lodging strong complaints, Japan called on South Korea to halt the drills, but Seoul flatly dismissed such calls and pledged to sternly respond to Japan's wrongful territorial claims to Dokdo.

South Korea has maintained effective control of the rocky outcroppings off the east coast with a small police detachment since 1945. Japan has persistently laid claim to Dokdo, drawing strong condemnation from Seoul.

The exercise began just three days after South Korea announced its decision to terminate the military information-sharing pact with Japan in response to Japan's export curbs on South Korea that began last month and its alleged refusal to make diplomatic efforts to resolve their rows stemming from its 1910-45 colonial rule of the Korean Peninsula.

Noting that the drills have been staged on a regular basis, however, presidential office spokesperson Ko Min-jung said the exercise is not aimed at any specific countries but to better fend off potential threats from "all forces."

Last month, a Russian warplane intruded into Korean airspace over Dokdo twice, while China and Russia were conducting their first joint air patrol. Over the course, two other Russian and Chinese military aircraft entered Korea's air defense identification zone (KADIZ) between Dokdo and South Korea's eastern island of Ulleung several times without prior notice.

Upon the conclusion of this exercise, the government reportedly will begin reviewing the timing and the scale of the second one scheduled for later this year.

"We have not fixed details for the second such exercise this year, as diverse factors including weather conditions should be considered. Whether to continue to stage the drills under the same name as this one will also be decided later in accordance with their scale and features," a Navy officer said.

Seoul-Tokyo ties recently have plummeted to their lowest point in years after Japan dropped South Korea from the list of its trusted trading partners earlier this month following the announcement of tighter export curbs on July 4 in apparent retaliation against the Seoul top court's ruling on wartime forced labor. (Yonhap)