Japan has officially removed South Korea from a list of trading partners entitled to simplified export procedures, further escalating an ongoing feud between the two countries. South Korea's Prime Minister is vowing to fight the move.
Under the new regulations, some companies will need to submit extra paperwork, slowing the export process.
Japan announced the change earlier this month. It went into effect Wednesday.
Japan's Chief Cabinet Secretary Yoshihide Suga says, "Japan made this decision to appropriately control our export system, because of national security concerns."
On Wednesday, South Korea's government held a meeting to discuss its next steps.
Seoul denies Japan's security explanation, instead saying the move is politically motivated and related to wartime grievances.
South Korean Prime Minister Lee Nak-yon says, "It is extremely regrettable that Japan has taken this unjust measure. We're repeating our demands for Japan to sincerely discuss ways not to worsen the South Korea-Japan relationship, but to mend it."
If diplomacy fails, South Korea has a back-up plan.
Its prime minister repeated the country's promise to appeal Japan's decision at the World Trade Organization.
In a sign of worsening ties, South Korea's foreign ministry summoned the Japanese ambassador in Seoul to protest Tokyo's latest move.
South Korea has also announced a new investment aimed at lessening the country's dependence on Japanese exports. It will inject more than 4 billion dollars into the high-tech industry, over three years.
South Korean companies are already feeling the effects of tighter export rules which went into effect last month.
The materials are necessary components for certain products, but can also be used to make weapons.