The defense ministry has referred to visiting military warships hoisting their own flag as standard practice in multinational maritime exercises as it dismissed concerns over the usage of the Japan Self-Defense Forces flag on Japanese warships in the Port of Busan.

The ministry’s spokesperson, Jeon Ha-kyu, revealed the stance in a press briefing on Thursday after being asked to comment on a report by a Japanese daily on a maritime interdiction exercise that will be held on the occasion of a high-level meeting of the Proliferation Security Initiative(PSI) in Seoul in late May.

Japan’s Yomiuri Shimbun earlier said that Seoul and Tokyo began discussing ways to have a destroyer from Japan’s maritime force enter the Port of Busan later this month for the planned drill under the flag of the Japan Self-Defense Forces.

Jeon said there are slight differences between the flag of the Self-Defense Forces and Japan’s “Rising Sun” flag, which is regarded by South Koreans and Asian countries as a symbol of Japan's wartime aggression and militarism in the first half of the 20th century.

Jeon said the defense ministry will apply the same standard to all PSI participants based on international practices and the principle of reciprocity.

The drill, called Eastern Endeavor 23, will commence in waters off Jeju next Wednesday with the aim of strengthening capabilities to counter the proliferation of weapons of mass destruction upon the 20th anniversary of the PSI.

A total of seven ships and six aircraft from South Korea, the U.S., Japan and Australia will take part in the multinational drill.