The South Korean Foreign Ministry on Thursday urged its Japanese counterpart to immediately revoke its boycott of Korean Air in protest of the airliner’s test flight over Dokdo in the East Sea.

“We see the measure as the Japanese government’s sanction against a Korean private company,” Seoul’s Foreign Ministry spokesman Cho Byung-jae told reporters.

“Reflecting on the current relations between the two countries, this kind of measure by Japan is highly disappointing and regrettable.”

The ministry has asked Tokyo to withdraw the measure, and keep from taking such measures in the future in consideration of the impact on bilateral relations.

Korean Air had reported its demonstration flight plan to the Land Ministry in advance.

“Korean Air obviously has the right to freely operate its flights in our airspace,” Cho said.

“We cannot accept any kind of protest by the Japanese government against our flag carrier’s flight in our own airspace. The Seoul government will respond in a firm manner to protect our territorial sovereignty.”

Japan’s Foreign Minister Takeaki Matsumoto has told his ministry officials not to fly with Korean Air for a month starting next Monday, taking the first ever step targeted at a private airline in connection with a territorial dispute, Japan’s Kyodo News reported.

Korean Air test flew its new Airbus A380 above Dokdo, South Korea’s easternmost islets which Japan claims as its own, on June 16, a day before the new plane went into service between Seoul and Tokyo. The jet carried executives of the airline as well as South Korean and foreign reporters.

Matsumoto has expressed concerns over the demonstration flight, describing the incident as “a violation of Japan’s airspace.”

Officials of the Japanese Embassy in Seoul visited the headquarters of Korean Air on Monday to protest the demonstration flight. Officials at the embassy declined to speak on the matter on Thursday.

A Korean Air spokesperson also declined to comment, simply mentioning that the Foreign Ministry has already expressed disappointment.

The Japanese foreign ministry reportedly concluded that ordering its officials not to fly Korean Air would not violate the World Trade Organization’s government procurement agreement. The South Korean foreign ministry, however, is looking into the possibility that it might.

By Kim So-hyun (sophie@heraldcorp.com)