The South Korean navy held a rare live-fire drill near a set of disputed islands yesterday, brushing off angry protests from co-claimant Japan, which called the exercises deplorable.
The defence ministry said the drill around the Seoul-controlled islets, called Dokdo by South Korea and Takeshima by Japan, was part of the military's "regular" national defence training.
The navy and coastguard have staged joint exercises near Dokdo many times, but a live-fire drill is rare and it prompted an angry response from Japan.
"Japan can never accept the drill given its position on Takeshima, and so we strongly demanded that the South Korean government stop its plans," Chief Cabinet Secretary Yoshihide Suga said in Tokyo.
Suga said the decision to push ahead with the exercises was "extremely deplorable".
Seoul dismissed the Japanese protests. A navy spokesman said the exercise was playing out defence scenarios against a variety of potential antagonists, "including North Korea".
Earlier this week, North Korean state media released pictures of leader Kim Jong-un overseeing a naval drill from the turret of a submarine.
"This is a military drill to bolster the defence of the Republic of Korea, so any outside demand or interference is not a subject for consideration," ministry spokesman Wi Yong-seop said.
"The drill is now being carried out as scheduled."
The rocky outcrops have been the subject of a bitter and decades-old territorial dispute between the two neighbours.
The row escalated in 2012 following a surprise Dokdo visit by then South Korean president Lee Myung-bak.
Relations between South Korea and Japan are at their lowest ebb for years, mired in emotive disputes linked to Japan's 1910-45 colonial rule, including the islet dispute.
Many South Koreans believe Japan has failed to properly atone for abuses carried out during the Japanese occupation.
Japan is also embroiled in a territorial dispute with China over a separate set of islands in the East China Sea.
The Japanese coastguard said two Chinese coastguard vessels had yesterday encroached within the 12-nautical-mile band around one of the Senkaku islands, which China also claims and calls the Diaoyus.