Japanese and South Korean officials on Monday clashed over what Tokyo alleges was a South Korean warship's directing of its fire-control radar onto a Japanese patrol plane flying over the Sea of Japan, in the latest sign of a deterioration in bilateral ties.

Kenji Kanasugi, director general of the Asian and Oceanian Affairs Bureau of the Foreign Ministry, said he told his South Korean counterpart Kim Yong-kil during their meeting in Seoul that the incident on Thursday was regrettable and urged South Korea to take steps to prevent similar cases from happening.

The South Korean side, however, complained about Japan's claim, saying that Tokyo is "making a case without clear confirmation of facts," according to a South Korean Foreign Ministry official.