SEOUL - South Korea on Friday staged drills in waters near a set of islets at the center of a brewing diplomatic row between South Korea and Japan.

The one-day joint defense drill, joined by the Navy and the Coast Guard, was aimed at deterring foreigners from trespassing into South Korea's territorial waters and making an illegal landing on the islets.

"The Coast Guard leads the defense drill based on a scenario where foreign civilians invade our waters," Col. Lee Boong-woo of the Combined Forces Command said during a press briefing. He refused to elaborate.

The exercise, launched in 1986, came amid a reignited dispute between South Korea and Japan over the sparsely inhabited islets in the East Sea (Sea of Japan) known as Dokdo here and Takeshima in Japan.

South Korean President Lee Myung-bak's high-profile visit to the South Korea-controlled islands last month drew strong protest from Japan, which subsequently proposed taking the issue to the International Court of Justice.

Officials here have repeatedly dismissed the proposal as "not even worthy of consideration," maintaining the islets are not an area in dispute.

Local reports say the South Korean government excluded the Marine Corps from the biannual drills this time around to keep diplomatic tensions from escalating.