Seoul called for the UN or another international body to investigate Japan's claims that some of its exports go to North Korea despite sanctions. Seoul and Tokyo have clashed over compensation to WWII forced laborers.
South Korea slammed "irresponsible comments" made by Japanese officials after Tokyo said Seoul cannot be trusted to implement sanctions on North Korea.
Last week, the Japanese government tightened the rules for exporting sensitive materials to South Korea, potentially hurting the country's TV and smartphone manufacturing. Separately, some Japanese media reported that Japanese hydrogen fluoride, which could be used for making chemical weapons, ended up North Korea.
On Friday, South Korean national security official Kim You-geun stated that his country has fully enforced UN sanctions on its northern neighbor.
"To halt unnecessary disputes and to determine factual basis of the Japanese government's claims, we suggest a panel of UN Security Council experts or an appropriate international organization to conduct a fair investigation," he said in televised statement.
If the probe showed Seoul was in the wrong, the government "will apologize for it and immediately apply measures to correct it," he added.
"If the result shows that our government has done nothing wrong, the Japanese government should not only apologize but also immediately withdraw the exports restrictions that have the characteristics of a (political) retaliation."
Bad blood over forced labor
Observers have linked the export dispute to the emotionally charged row over Korean forced labor and forced prostitution. Last year, South Korean courts ordered Japanese companies, including Mitsubishi, to pay for using slave labor during the Japanese occupation of Korea. Tokyo has slammed the decision as "totally unacceptable."
Japanese officials have denied that sanctions were connected to the forced labor issue. However, Japanese Trade Minister Hiroshige Seko referred to the row while announcing the measure, saying that South Korea's position had damaged trust.
Export officials from both sides were meeting in Tokyo on Friday.