South Korea's Foreign Ministry is expressing concerns over a directive issued by Japan's government that could affect the communications sector.

The ministry said on Saturday that none of the country's firms should face discriminatory measures over Tokyo's directive issued to the operator of the popular Line social media app to quickly review capital ties with a South Korean IT firm.

Earlier this month, Japan's communications ministry issued a directive for the second time against LY Corporation, better known in Japan as Line Yahoo, following a massive leak of Line user data.

The directive calls on the firm to carry out a prompt group-wide review of capital ties with South Korean IT firm Naver, which was blamed for the data breach.

Naver has a 50-percent stake in LY Corporation's parent firm.

The South Korean Foreign Ministry said it will check the intention of Naver, and if necessary, will hold talks with Japan.

The issue has also created tension in South Korea.

An editorial in the major conservative newspaper, Chosun Daily, says Japan's attempt to dissolve a joint business relationship between private companies is "anticompetitive behavior" and "likely violates" a 2003 bilateral investment agreement.

The daily says what it sees as Japan's "unfair pressure" on Naver "should immediately stop."